Alternative Armour Thoughts

[rickshaw]

Leaf-springs are unhardened.  HVSS/VVSS are encased for the most hard in hardened housings and so less vulnerable.  If you use large wheels with leaf-springs, you can make the wheels armoured and therefore protect to a large extent the springs, behind them but the big wheels themselves then become a target - not for deliberate shots so much but the stray splinters which fly 'round battlefields.

As for the applicability of leaf-spring suspension any nation with a moderate automotive building industry can produce leaf-springs.   The Krupp proposal for the Panther featured them.  Might have saved them a lot of trouble if they'd adopted that one over the Rheinmetall torsion bar suspension.

[dy031101]

Moved from my mental note thread.

I butchered various KV drawings taken from here, basically a combination of KV-1S hull and KV-5 weapons.  The top one is there due to my fascination for tanks with secondary MG turrets.  I would have bought the KV-5 in World of Tanks if it wasn't so big...... I mean, I thought the combination of a multi-turret design and a high-velocity 107mm cannon to be pretty cool, but the KV-5 is just too dang big for my liking (and so is the KV-2 turret required to put that 107mm on the basic KV)......



Wait a friggin' minute, why do I now feel like I'm not the first person to think of this combo? 

[Mr.Creak]

What's T-28's turret ring size?

I don't have that information.

Just wonder if the T-34 could have taken the gun.

A "normal" T-34 was 1600 mm but there was a variant taken up to 1700 mm - the T-34/ 100.

[dy031101]

Hum...... I forgot that the British Cruiser Tank Mk.I is another design that incorporated two auxiliary MG turrets.



Could be a better inspiration source for me- this one is a cruiser tank, not an infantry tank like the T-28 or a heavy tank like the 25TP.  And I've always been under the impression that cruiser tanks are closer to a generic medium tank than infantry tanks are.  Adjust the hull to allow for a turret and associated turret ring accommodating a US 90mm or British 20-pounder, do a new engine deck with fewer shot traps, swap in a leaf spring suspension system, maybe change the auxiliary turrets to a non-cylindrical design, and that'd be the starting point......

Sounds like it was throwing tracks all the time though.  Why was that?  Did its derivative Valentine infantry tank suffer the same problem?

(And would the problem persist if the suspension gets replaced with a leaf spring system as previously discussed?)

[rickshaw]

Have you wondered why multi-turreted designs were abandoned?

They were abandoned for the same reason that naval battleships abandoned sponson mounted guns on the hull sides.  The turrets are both shot traps and present weaker armour.  On naval ships they were also rather "wet", letting water into the hull but thats by-the-by.  However, it was primarily that their armoured shields were weaker than the main armour belt, so that when a shell penetrated, all they did was kill their crews (as their guns were too short ranged to respond) and potentially led to ammunition explosions, which in turn could cripple the ship.

On tanks, because the MG turrets were more thinly armoured than what was needed on the front of the tank, they weakened the tank and made it more likely to be penetrated.  Even if not penetrated, they were easily jammed by a non-penetrating shot, rendering them useless.   So, while they had a brief fashion, after battle experienced showed that you needed to present the maximum amount of armour possible to the enemy, particularly in the frontal arc, they were abandoned.

[dy031101]

Nah, I'm just thinking of a barely-serviceable fantasy tank, that's all.

[Weaver]

That Cruiser Mk.1 is pretty much all shot-trap and no tank: even the bits that are relatively conventional have shot-traps specially designed into them.....

On tanks, because the MG turrets were more thinly armoured than what was needed on the front of the tank, they weakened the tank and made it more likely to be penetrated.  Even if not penetrated, they were easily jammed by a non-penetrating shot, rendering them useless.   So, while they had a brief fashion, after battle experienced showed that you needed to present the maximum amount of armour possible to the enemy, particularly in the frontal arc, they were abandoned.

Also, there's a sheer surface area issue. Consider a crewman sitting in the front of a conventional tank: his upper body only needs armour to it's front, one side, and the top. Now put him in an MG turret and his upper body needs armour to front, back, top and both sides, and the hull next to his back and his "inboard side" needs a layer of armour too. Given that a tank can only carry a certain weight of armour for a given size, power and armament, a multi's armour will ALWAYS be thinner becuase it's spread over a greater surface area. Then factor in how much less efficient a multi's armour is due to shot-traps, vertical plates, lots of closely-spaced joints etc.....

[pyro-manic]

Plus the extra space/weight requirements for ammunition and supporting the extra crewmen. Also bear in mind that the early Cruisers were small, and had thin armour anyway. There's

I have pondered the idea of auxiliary turrets mounted on the main turret. Perhaps not very feasible until you get to the MBT70 or later Western tanks with their enormous flat turrets, and by then remote stations are a much better idea, but it would be interesting to see. Or a multitude of small turrets on a WWI-style tank, instead of (or as well as!) the sponsons.

[Weaver]

Well you have the M48 and M60 whose cupolas are effectively mini-turrets, and most other commander's cupolas could be considered a mini-turret with an externally-mounted weapon.

I CAN see one form of multi-turret that has some merit, and that's the rear position as on the Char-2C. This is basically an extra compartment behind the engine with a one-man turret on top. It doesn't compromise the armour scheme too much (the gunner's behind armour that would be there anyway), and the command and control issue is eased by the rear gunner having a clear, single "mandate": stop enemy infantry from creeping up to the sides and rear. The rear gunner's non-combat role could be as a mechanic/engineer, akin to the flight engineer on a bomber. His compartment could have a greater range of instruments to monitor the engine than the over-crowded driver's station could accomodate. He could also have emergency driving controls of his own for emergency escapes. This scheme would probably be most useful on a tank intended primarily for urban warfare.

[rickshaw]

Plus the extra space/weight requirements for ammunition and supporting the extra crewmen. Also bear in mind that the early Cruisers were small, and had thin armour anyway. There's

I have pondered the idea of auxiliary turrets mounted on the main turret. Perhaps not very feasible until you get to the MBT70 or later Western tanks with their enormous flat turrets, and by then remote stations are a much better idea, but it would be interesting to see. Or a multitude of small turrets on a WWI-style tank, instead of (or as well as!) the sponsons.

Actually the room inside of the M1 turret is quite small.

Yes.  Its something to do with all that armour, I believe.

I'm unsure why people think you need extra turrets.  If your no.2 isn't covering your six, then he should be!

[pyro-manic]

I was referring to the large area of "deck" space on top of the turrets of the Abrams, Challenger et al, rather than the interior space. Of course adding a turret would mean less armour and ammunition storage.

[Joe C-P]

The US Lee M3 tank had a cupola with a machine gun on top of the 37mm turret.

Multiple turrets are only useful if there is both the requirement and the ability to engage multiple targets nearly simultaneously. For an infantry support tank, where only enemy personnel are expected to be engaged, then multiple light weapons with different fields of fire are useful. If instead you want the heaviest primary weapon, then the secondary weapon(s) should not detract from that and only serve defensive purposes.

But I'm still building a multi-turret land-ship someday, practicality be darned! 

[dy031101]

For an infantry support tank, where only enemy personnel are expected to be engaged, then multiple light weapons with different fields of fire are useful. If instead you want the heaviest primary weapon, then the secondary weapon(s) should not detract from that and only serve defensive purposes.

Come to think of it, why did the British put MG turrets onto the Cruiser Mk.I?

I'm thinking of taking some inspirations from it (for a fantasy tank that would be an equivalent of a real-life Interwar-era tank but would remain barely serviceable by late-War standard...... like putting 95mm gun F-39 on the T-29...... kind of) due to its being relatively fast compared to the T-28 and probably 25TP, but a cruiser tank is meant to exploit a breakthrough, not to support infantry, right?

EDIT: Might as well ask for clarification on what the earliest cruisers are meant to go after with their 2-pounder......  

[raafif]

EDIT: Might as well ask for clarification on what the earliest cruisers are meant to go after with their 2-pounder.

they were meant to go after German bunkers ....
                 knock politely on the door with the 2pdr shell ....
                                                  and ask if they may come in.

"I say old chap, do you mind if we just stroll on through ?"  [posh, upper-class accent OFF]

[rickshaw]

For an infantry support tank, where only enemy personnel are expected to be engaged, then multiple light weapons with different fields of fire are useful. If instead you want the heaviest primary weapon, then the secondary weapon(s) should not detract from that and only serve defensive purposes.

Come to think of it, why did the British put MG turrets onto the Cruiser Mk.I?

Because the role of the Cruiser tank was similar to that of traditional cavalry - exploitation after a breakthrough.  That meant they expected to primarily be engaging infantry fleeing the battlefield and rear support troops rather than tanks.

I'm thinking of taking some inspirations from it (for a fantasy tank that would be an equivalent of a real-life Interwar-era tank but would remain barely serviceable by late-War standard...... like putting 95mm gun F-39 on the T-29...... kind of) due to its being relatively fast compared to the T-28 and probably 25TP, but a cruiser tank is meant to exploit a breakthrough, not to support infantry, right?

EDIT: Might as well ask for clarification on what the earliest cruisers are meant to go after with their 2-pounder......  

You are correct that cruisers were intended to exploit a breakthrough.  As to what their 2 Pdr was intended for, it was obviously intended, as was that of the 2 Pdr on infantry tanks to engage other tanks.   It was understood that one of the things the enemy does to prevent a breakthrough is to rush reinforcements to contain it and counter-attack.  Some of those reinforcements would of course be tanks, so obviously an AT facility was needed for the Cruisers, just as it was for the Infantry tanks.

What you have to understand is that the British "ethos" (they did not have a doctrine, per se) in battle was for the artillery to take care of strong point destruction.  Tanks were to support infantry - with their machine guns.  Tank guns were intended to be used as AT weapons, not to destroy strong points.   Obviously this ethos was somewhat divorced from reality but it was based on the successful experience of WWI's One Hundred Days.  It wasn't until about 1942 that British commanders started seriously discussing the need for a "universal tank" which could fire both HE and AP and that was based upon their experiences with M3 and M4 mediums in the Western Desert.