new big 'Ogre' tank that combines functions of tank and self-propelled howitzer?

[T. A. Gardner]

I agree that the existing method of adjusting a 155mm howitzer's muzzle energy (by varying sizes of propellant bags), while acceptable for an Ogre's leisurely shooting day, wouldn't work in an all-out fight. I don't know how best to accomplish the needed variable muzzle energy, and of course I'm not demanding a laid-out solution from you all. It's too bad that liquid propellants haven't worked out. Ogre would necessarily start as a research project, not something that could be built next year even given a "waste everything except time" unlimited budget (unless DARPA is driving something around the salt flats of Groom Lake that we don't know about). I suggested to Foo Fighter that the project for a replacement for the M1 when that successful tank at last becomes obsolescent in another decade or so should start today.

Railguns powered by superconducting capacitors, lasers or particle beams that could melt through current tank armor in a fraction of a second without thermal blooming, anti-kaiju Atomic Heat Ray Guns or Maser Cannons, etc., if they ever work at all, are weapons for the generations after Ogre, and therefore are not covered in this thread. Ogre would be a relatively conventional tank, somewhat bigger, with the next generation of defense, firepower, and mobility, whose one all-new feature is being able to provide direct and indirect fires with equal facility, to win out over tomorrow's threats.

One way to vary it would be to use a high-low pressure gun with gas venting. The PAW 600 is such a weapon without the venting. What you have with such a gun is a variable muzzle velocity with the same charge being used. Of course, if you want high velocity, that isn't the way to go because you won't have it in any setting.

I'm being lazy so here's the intro version:

High–low system - Wikipedia

en.wikipedia.org

 

[Scott Kenny]

I agree that the existing method of adjusting a 155mm howitzer's muzzle energy (by varying sizes of propellant bags), while acceptable for an Ogre's leisurely shooting day, wouldn't work in an all-out fight. I don't know how best to accomplish the needed variable muzzle energy, and of course I'm not demanding a laid-out solution from you all. It's too bad that liquid propellants haven't worked out. Ogre would necessarily start as a research project, not something that could be built next year even given a "waste everything except time" unlimited budget (unless DARPA is driving something around the salt flats of Groom Lake that we don't know about).

Honestly, I think that the next advancement in tanks is going to be another type or two of ammunition. Still got long rods and HEAT for direct fire, now we're adding two mid-range munitions: one fast for the flat plains of Iraq or Kursk 3, one slow for built up areas and mountains of Korea 2.

I suggested to Foo Fighter that the project for a replacement for the M1 when that successful tank at last becomes obsolescent in another decade or so should start today.

100% agree with that. Army has been sitting on the Abrams too long and absolutely needs a new tank design cooking.

Ogre would be a relatively conventional tank, somewhat bigger, with the next generation of defense, firepower, and mobility, whose one all-new feature is being able to provide direct and indirect fires with equal facility, to win out over tomorrow's threats.

You mean 2 new features: all around armoring and APS to protect against top attack and FPV kamikazes, plus the mid range shooting.

 

[Owens Z]

One way to vary it would be to use a high-low pressure gun with gas venting. The PAW 600 is such a weapon without the venting. What you have with such a gun is a variable muzzle velocity with the same charge being used. Of course, if you want high velocity, that isn't the way to go because you won't have it in any setting.

I'm being lazy so here's the intro version:

Thanks, T.A. Take a look at < https://www.secretprojects.co.uk/threads/rarefaction-wave-gun-raven.14469/ > too, about the rarefaction wave gun (RAVEN) project. Basically, a big gun's breech is opened after the projectile is already far down the barrel, so that no muzzle energy is lost, but the gases venting rearward substantially reduce (c50%?) the felt recoil. Apparently successful tests, but no news thereafter about actual applications.

 

[Scott Kenny]

Thanks, T.A. Take a look at < https://www.secretprojects.co.uk/threads/rarefaction-wave-gun-raven.14469/ > too, about the rarefaction wave gun (RAVEN) project. Basically, a big gun's breech is opened after the projectile is already far down the barrel, so that no muzzle energy is lost, but the gases venting rearward substantially reduce (c50%?) the felt recoil. Apparently successful tests, but no news thereafter about actual applications.

I like the concept, but I suspect that the RAVEN gun ran afoul of backblast.

You can't have infantry shelter behind a tank with a RAVEN gun and be able to use that gun. And that makes it extremely difficult for the tank to be used in urban combat to blast strongpoints.

 

[Owens Z]

Unfortunately this thread lost two or three valuable posts during the recent emergency backup. But Scott Kenny, DWG, and I were in agreement that the rarefaction wave gun (RAVEN) concept doesn't seem suitable for a new tank. No news about RAVEN from any Army higher-ups in the past fifteen years or so, so it appears that they agree too.

 

[Owens Z]

The tank for this gun is "Nota"

The longtime Soviet/Russian standard caliber for tanks is 125mm (also adopted by Communist China), and the similar standard for NATO and allies is 120mm, especially variants of the Rheinmetall Rh-120 gun. For many generations, the respective artillery calibers have been six inches (152.4mm) for Russia, and the similar French-originated 155mm for the West, as being about the limit for shells that fit young men can load for extended firing. Since at least the time of Object 292, Russian designers have worked to arm their tanks with a 152.4mm gun, for a big leap in firepower, although so far no production has resulted. If the modern Russian 2A83 gun design (or a knockoff in China) ever does enter service in numbers, then I suspect that further development of the 45-year-old Abrams tank will no longer be thought adequate for the US Army and others. The 2A83 is smoothbore, and hence presumably cannot shoot regular 152.4mm artillery shells. While thus not being the equivalent of the conjectural rifled 155mm gun of the Ogre tank that is the subject of this speculative thread, still a formidable weapon. Could the armor of any in-service tank survive a hit from an APFSDS penetrator sized for a 152.4mm gun?

 

[Scott Kenny]

Could the armor of any in-service tank survive a hit from an APFSDS penetrator sized for a 152.4mm gun?

Unlikely, though it also depends on just how long the penetrator is.

 

[Dilandu]

Could the armor of any in-service tank survive a hit from an APFSDS penetrator sized for a 152.4mm gun?

At this point you could just use old-style AP shell with bursting charge inside. The multi-layer armor of modern tanks are not optimized against the heavy AP shells, which rely on their weight & velocity to penetrate.

 

[Scott Kenny]

At this point you could just use old-style AP shell with bursting charge inside. The multi-layer armor of modern tanks are not optimized against the heavy AP shells, which rely on their weight & velocity to penetrate.

Can a 152mm AP shell penetrate more than 700mm of RHA equivalent?

 

[Dilandu]

Can a 152mm AP shell penetrate more than 700mm of RHA equivalent?

Easily. Since while its RHA equivalent against APFSDS and shaped charges, against AP shell its essentially two thin sheets of metal with some funny porcelaine or glass inbetween. It would just smash through, not being stopped or deflected.

 

[paralay]

The 152 mm projectile has one significant advantage, it can be nuclear

 

[Scott Kenny]

Easily. Since while its RHA equivalent against APFSDS and shaped charges, against AP shell its essentially two thin sheets of metal with some funny porcelaine or glass inbetween. It would just smash through, not being stopped or deflected.

Not that thin, IIRC the Abrams outer panels are on the order of ~4"/100mm thick with another 4"/100mm on the inside to support the armor weight. Plus more than just ceramics/glass on the inside.

The 152 mm projectile has one significant advantage, it can be nuclear

It's physically possible to make a 120 or 125mm nuclear round, it just uses a lot of plutonium.

 

[Nik]

Logistics, logistics, logistics...

Cannot make chassis wider, as won't fit aboard vehicle fleet, cross bridges etc.
Cannot make chassis longer as, beyond certain length : width ratio, tracks scuff.

Um, has anything since the T28/T95 prototypes used dismountable track sponsons ?? Would also seem handy for affixing reactive armour etc etc...

Also, manual / semi-manual loading would seem to need a really wide turret ring for big enough basket for sufficient main-gun elevation to play 'howitzer', too.

Accepting conventional turret simply cannot do both without a shot-trap, must tank design add VLS ??

FWIW, wasn't Gavin Lyall's 'Uncle Target' McGuffin, a prototype tank with gel-propellant main gun; chased across Jordanian desert by all and sundry ??

 

[Scott Kenny]

Um, has anything since the T28/T95 prototypes used dismountable track sponsons ?? Would also seem handy for affixing reactive armour etc etc...

I do not believe so. Those are a right PITA to worth with, and require a suspension designed for the purpose. You can't build them with torsion bar suspensions, you'd need something that bolts onto the side of the hull instead.

Though I should add that "suspension units that just bolt onto the side of the hull" also allows you to do more under hull shaping for mine/IED resistance without adding height to the vehicle. See Merkava for an example, it uses coil springs on the suspension arms bolted to the outside of the hull.

Also, manual / semi-manual loading would seem to need a really wide turret ring for big enough basket for sufficient main-gun elevation to play 'howitzer', too.

Accepting conventional turret simply cannot do both without a shot-trap, must tank design add VLS ??

Turret-ring diameter is defined by the gun's recoil stroke, not elevation. You need to be able to have the gun not slam into the turret ring when the gun elevation is such that it is in line with the turret ring or basket.

I think that a VLS is likely, but not for artillery weapons per se. Just for Loitering Munitions and/or recon drones.

 

[T. A. Gardner]

I do not believe so. Those are a right PITA to worth with, and require a suspension designed for the purpose. You can't build them with torsion bar suspensions, you'd need something that bolts onto the side of the hull instead.

Though I should add that "suspension units that just bolt onto the side of the hull" also allows you to do more under hull shaping for mine/IED resistance without adding height to the vehicle. See Merkava for an example, it uses coil springs on the suspension arms bolted to the outside of the hull.



Turret-ring diameter is defined by the gun's recoil stroke, not elevation. You need to be able to have the gun not slam into the turret ring when the gun elevation is such that it is in line with the turret ring or basket.

I think that a VLS is likely, but not for artillery weapons per se. Just for Loitering Munitions and/or recon drones.

You also have to have room between the turret ring and the breech to load rounds, unless you want a fixed loading position (like the T 62) that slows down rate of fire.

Then there's things like, how do you load something like a 28 cm gun without including a loading tray and power ramming? Next comes using bagged versus cased charges. Then there's the issue of smoke and fumes clearance meaning you need a pneumatic system.

You'll also need some system to move shells and charges from the magazine / bins / racks to the turret meaning some sort of hoist system. None of this can be done manually. It also argues that you end up with a fixed position loading system.

Seems kind of pointless to have guns that big unless you add some sort of advanced, ship-like, fire-controls to the vehicle. If all you have are the sort of stadia telescopic sights tanks of that era had you are limited to maybe 5,000 meters of reasonably accurate fire. It seems a total waste to build such a vehicle to be little more than a self-propelled artillery piece as an alternative.

 

[Scott Kenny]

You also have to have room between the turret ring and the breech to load rounds, unless you want a fixed loading position (like the T 62) that slows down rate of fire.

Sure, but usually the recoil stroke length of the gun is at least equal to if not exceeding the length of the projectile.

Then there's things like, how do you load something like a 28 cm gun without including a loading tray and power ramming? Next comes using bagged versus cased charges. Then there's the issue of smoke and fumes clearance meaning you need a pneumatic system.

You'll also need some system to move shells and charges from the magazine / bins / racks to the turret meaning some sort of hoist system. None of this can be done manually. It also argues that you end up with a fixed position loading system.

Seems kind of pointless to have guns that big unless you add some sort of advanced, ship-like, fire-controls to the vehicle. If all you have are the sort of stadia telescopic sights tanks of that era had you are limited to maybe 5,000 meters of reasonably accurate fire. It seems a total waste to build such a vehicle to be little more than a self-propelled artillery piece as an alternative.

But today we do have ship-like fire control systems in tanks and artillery.

Remember, this is a modern/near future vehicle that may have a bigger gun and does have artillery levels of gun elevation. We're not talking about some Landkreuzer Ratte here, we're talking about an OGRE Mk1 that's maybe 50% bigger than an Abrams at most.

 

[T. A. Gardner]

Sure, but usually the recoil stroke length of the gun is at least equal to if not exceeding the length of the projectile.

That depends on the recoil system. You can get a really short recoil, even if it is somewhat violent.

But today we do have ship-like fire control systems in tanks and artillery.

Remember, this is a modern/near future vehicle that may have a bigger gun and does have artillery levels of gun elevation. We're not talking about some Landkreuzer Ratte here, we're talking about an OGRE Mk1 that's maybe 50% bigger than an Abrams at most.

But those systems on tanks are set up to like 5000 meters or so because that's the expected maximum engagement range. An Ogre would really need something that could let it outrange any opponent other than another Ogre. That means you need something that works at say, 10,000 to 15,000 meters at least.

True Ogre vehicles are in the absurdly large region of at least 1000 tons...

 

[Scott Kenny]

That depends on the recoil system. You can get a really short recoil, even if it is somewhat violent.

You can, but lighter vehicles like a longer recoil stroke. Crud, the recoil stroke on a 16"/50 Mk7 (Iowa main gun) is 14-18ft and is violent enough to kill someone even at the very end of the stroke!

But those systems on tanks are set up to like 5000 meters or so because that's the expected maximum engagement range. An Ogre would really need something that could let it outrange any opponent other than another Ogre. That means you need something that works at say, 10,000 to 15,000 meters at least.

Artillery fire controls already exist. You're just fitting both conventional tank and conventional artillery FCS in the same vehicle.

True Ogre vehicles are in the absurdly large region of at least 1000 tons...

I am running on the idea here as being "a vehicle with Abrams frontal protection across the full 180x360 arc while still being small enough to be strategically mobile"

 

[T. A. Gardner]

You can, but lighter vehicles like a longer recoil stroke. Crud, the recoil stroke on a 16"/50 Mk7 (Iowa main gun) is 14-18ft and is violent enough to kill someone even at the very end of the stroke!



Artillery fire controls already exist. You're just fitting both conventional tank and conventional artillery FCS in the same vehicle.



I am running on the idea here as being "a vehicle with Abrams frontal protection across the full 180x360 arc while still being small enough to be strategically mobile"

 

[Dilandu]

Logistics, logistics, logistics...

Cannot make chassis wider, as won't fit aboard vehicle fleet, cross bridges etc.
Cannot make chassis longer as, beyond certain length : width ratio, tracks scuff.

That's why I suggested the idea of tank with modular side/rear armor, which could be added when required and dismounted for transportation.

 

[Scott Kenny]

That's why I suggested the idea of tank with modular side/rear armor, which could be added when required and dismounted for transportation.

I'm not totally happy with that idea, because it makes the vehicle exceptionally vulnerable during transportation. Also, doing that more or less halves the transport capacity of a ship, and may require two Tank Transporters on roads.

But if the requirement is "Abrams protection across all arcs", I don't see any other way to do that. Which may even require T28 Superheavy "Doom Turtle" style additional track units to bolt onto the outside.

 

[Dilandu]

I'm not totally happy with that idea, because it makes the vehicle exceptionally vulnerable during transportation. Also, doing that more or less halves the transport capacity of a ship, and may require two Tank Transporters on roads.

I'm not talking about tank without armor. My idea is more or less a two-mode tank.

* The "battle tank mode" (also the transport mode) - 60-80 tons tank with heavy armored front and lightly armored sides (as most main battle tanks have), reasonably mobile, transportable;

* The "assault tank mode" - the additional armor plates are put on sides and rear, bringing tank total weight to 120-150 tons. The mobility decreased, but the tank now have all-around heavy armor and could be used to break enemy defense lines;

 

[Scott Kenny]

I'm not talking about tank without armor. My idea is more or less a two-mode tank.

* The "battle tank mode" (also the transport mode) - 60-80 tons tank with heavy armored front and lightly armored sides (as most main battle tanks have), reasonably mobile, transportable;

* The "assault tank mode" - the additional armor plates are put on sides and rear, bringing tank total weight to 120-150 tons. The mobility decreased, but the tank now have all-around heavy armor and could be used to break enemy defense lines;

Right, but any modern ATGM is capable of defeating "normal" side or top armor.

 

[shin_getter]

Have you all wonder about a ground penetrating projectile that also have a upward EFP, to attack the bottom armor? Things are fun when armor defeat projectiles can scale up with the defenses at head.

*ultimately the inability to armor sensors or mobility features means this wouldn't really be needed though.

 

[Scott Kenny]

Have you all wonder about a ground penetrating projectile that also have a upward EFP, to attack the bottom armor? Things are fun when armor defeat projectiles can scale up with the defenses at head.

Land mines like that would need a whole lot of standoff, which means dug in deep.

Which is highly impractical.

*ultimately the inability to armor sensors or mobility features means this wouldn't really be needed though.

Eh, you can also make significantly-redundant sensors so it's hard to blind the vehicle. The bigger threat will always be the mobility kill.

 

[Dilandu]

Well, there are rocket-delivered AT mines, and there are roof-attacking mines (that detect enemy vehicle & shot upward the homing projectile - which orient itself, find enemy vehicle with small seeker and shot an explosive-formed penetrator in the roof)

 

[Scott Kenny]

Well, there are rocket-delivered AT mines, and there are roof-attacking mines (that detect enemy vehicle & shot upward the homing projectile - which orient itself, find enemy vehicle with small seeker and shot an explosive-formed penetrator in the roof)

Yes, those are a significant threat.

But IMO the underbody threat can be defined as about 25kg of TNT.

 

[Nik]

A mischievous notion for the high-arc stuff: A telescopic turret ?
Usual position for 'Line of Sight' business, so low-ish profile, minimal 'shot trap'.
Entire basket rises ~50 cm for high elevation ??

Okay, go on, giggle at this 'easter bunny'...

 

[Scott Kenny]

A mischievous notion for the high-arc stuff: A telescopic turret ?
Usual position for 'Line of Sight' business, so low-ish profile, minimal 'shot trap'.
Entire basket rises ~50 cm for high elevation ??

Okay, go on, giggle at this 'easter bunny'...

I mean, it'd take some significant hydraulics to lift the turret up, turret weights are likely on the order of 20-30 tonnes. Not counting all around protection.

I think you'd be better off with hydropneumatic suspension to pull S-tank shenanigans with the hull to increase gun elevation.

 

[Owens Z]

Can a 152mm AP shell penetrate more than 700mm of RHA equivalent?

Easily. Since while its RHA equivalent against APFSDS and shaped charges, against AP shell its essentially two thin sheets of metal with some funny porcelaine or glass inbetween. It would just smash through, not being stopped or deflected.

In the first post of this thread, I did mention a new 155mm shell for the Ogre inspired by the US Navy's successful six-inch Mark 35 'super heavy' 130-lbs (59kg) projectile, of which 2 lbs was Explosive D. And the US Army's T30 tank of 1945 had a 100-lbs APHE projectile specially designed for its 155mm gun. But I don't figure a 155mm round could penetrate a rolled homogeneous armor equivalent (RHAe) thickness of more than about twice its diameter, because a hefty full-bore APHE shell cannot be boosted to the high velocity that a saboted subcaliber penetrator can.

So more for demolition effect than for deepest piercing. But current active protection systems aboard AFVs, designed to fight lightweight penetrators and flimsy antitank missiles, might have trouble with the solidity of an incoming APHE round.

 

[Owens Z]

The 152 mm projectile has one significant advantage, it can be nuclear

It's physically possible to make a 120 or 125mm nuclear round, it just uses a lot of plutonium.

By mutual agreement, the US Army's and Soviet Army's stocks of atomic shells were removed from service in the early 1990s. Let's not give anybody ideas, Scott Kenny—the 2020s have enough problems as it is.

 

[Owens Z]

...Then there's things like, how do you load something like a 28 cm gun without including a loading tray and power ramming?

...True Ogre vehicles are in the absurdly large region of at least 1000 tons...

A thousand-ton vehicle? With 28 cm naval guns? What? Who?

You're on the wrong floor—you want < https://www.secretprojects.co.uk/threads/could-giant-tanks-make-a-comeback.45005/ > instead.

 

[Owens Z]

In 1944-45 the Soviet ISU-152 assault gun was armed with a version of the 152.4mm ML-20 gun/howitzer, and its ordinary HE shell was big enough to be devastating against the heaviest German AFVs when directly hit. The American equivalent of the ML-20, the 155mm M1 Long Tom, was installed successfully in T30 tanks in 1945 (although the T30 subsequently didn't enter production). And self-propelled high-elevating 155mm howitzers have been common since the M41 eighty years ago (and with 360-degree-traverse turrets since the M109 more than sixty years ago). Thus the objection "impractical to fit a gun of this size" is unconvincing. In fact, according to the thirdhand reports I have seen, Object 292, with a custom-design 152.4mm smoothbore gun in a modified T-80 chassis and no heavier than an ISU-152, shot and handled well during tests until the collapse of the Soviet Empire ended that secret project. It is true that, as far as I can tell, Object 292 made no attempt to proof itself against enemy guns of similar caliber, for which more weight would have been necessary. And like usual for postwar Soviet tanks, the elevation of Object 292's monster gun was quite constricted. So not the exact equivalent of an Ogre, which as discussed earlier in this thread would be a new concept requiring a research and development program.

 

[Owens Z]

No vehicle will be invincible and its crew untouchable (since HMS Warrior of 1860 anyway). The goal of Ogre is not perfection, but to be a realistic leap ahead to a meaner, more-versatile, bigger-but-manageable, affordable-in-numbers AFV that regains the utter battlefield dominance which the M1 Abrams (and Challenger 1 tank) demonstrated by mowing down thousands of Soviet-built Iraqi tanks in four days during 1991's Desert Storm. Trying to stuff into a new design anything and everything that might possibly be useful in some scenario (by people who told us they are concerned about weight gain) shows a lack of ability to judiciously sift through trade-offs, like a true AFV designer must. We don't need Maus weight. And we don't want a program like the failed MBT-70 again.

 

[Scott Kenny]

By mutual agreement, the US Army's and Soviet Army's stocks of atomic shells were removed from service in the early 1990s. Let's not give anybody ideas, Scott Kenny—the 2020s have enough problems as it is.

Sorry, but "Czar Vlad and the events of 2022" kinda showed that nuclear proliferation was going to be the way forward.

No, it doesn't help me sleep better at night either.

We don't need Maus weight.

I think "Abrams frontal protection across 360deg" leads us towards Maus weight.