Why Can’t Tanks be Larger? Rheinmetall’s 130mm Gun and the Future of MBTs

[daftandbarmy]

6A Course.  Lawfield Corridor.  Late January 1985.

Tank became bogged on one of the Traces.  It had broken through a layer of ice.  Crew got out and left hatches open as it was not down below the top of tracks.  ARV hooks up and begins Recovery.  Tank breaks through a second layer of ice below top layer and is dragged to the bottom.  ARVs pull it out, and haul it back into K17.  Sat in hangar all night and this is what we found when we came in the next morning.  Drivers hatch full of mud.  Icicles hanging down like prison bars in the Loader and CC hatches.  AMU ripped off.  Mud on back deck making it look like a "Fastback".  Notice the 12" block of ice still rammed up between gun and glacis plate.  Over $65K damage.  First C Sqn tank to go to "rebuild" in Montreal.

Cool.... that looks just like an 'Infantry Tank'

 

[GR66]

While the idea of bigger and bigger guns has been around for a long time (look at the 140mm M-1 test bed, this was the mid 1980's...), practical considerations of weight, the mass of the ammunition and even the amount of ammunition that can be carried means that it isn't as easy as just sticking a bigger gun in the gun cradle. If anything, the Merkava might be the model for a "gun tank" in the future, with a low profile or even unmanned "cleft" turret to reduce the armoured volume up top, engine in the front to provide more protection across the frontal arc and a large rear area in the hull to carry the massive 130-140mm rounds in sufficient quantity.

It might be more feasible to think of a future tank as a mobile, protected fire support platform using smart or top attack rounds to engage a wide variety of targets (and also expand the range of tank engagements). Rounds like KSTAM provide the ability to prosecute top attack engagements out to 8km, and LAHAT out to 13 km with a forward observer (could be dismounted infantry, helicopter or even UAV)

With long range capabilities like this or similar options like Spike-NLOS where you don't have to expose your launch vehicle to direct enemy fire, could you drop the heavy armour and have more plentiful, cheaper launch platforms (maybe mounted on something like the British Wolfhound), guided by plentiful observer platforms to take out enemy AFV's instead of traditional MBT's? 

Would tanks then maybe be left to focus more on an "assault gun" type role to move against defined and entrenched enemy positions after their maneuver forces in the open have been eliminated by other means?  Would then as you mentioned, a design more similar to the Merkeva than a Leopard II or M1 be more appropriate?

 

[Colin Parkinson]

The Merk is designed knowing the battlefields they will have to fight on, they even kept the Horstman suspension system of the Centurion that performed well in the rocky terrain of the Golan. It’s tougher for an expeditionary force that has no real firm idea where and whom they will fight next. The demise of the tank has been around since about their first battle. In the next 10 years you might find that longrange ATGM fire being countered by lasers either on individual tanks or on dedicated anti-ATGM vehicles. Modern MBT’s are still tough nuts to crack and not everyone will have access to ATGM’s. Right now the ATGM is entering it’s 2nd glory day, since the inception of the Sagger in the 73 war. But there are lot’s of potential countermeasures as well.
I note the US is trying to shave 6-7 tons off of the M1 with a lighter gun and power pack, so you might see a “heavy version” with 130mm gun for facing off modern threats and “light version” for the various expeditionary forces using the lightweight 120mm. 

 

[a_majoor]

GR66, I'm thinking of the evolved gun tank as a vehicle which still needs protected mobility to survive on the modern battlefield. Enemy rounds will manage to "leak" through various countermeasures, brave or suicidal infantrymen could still pop up at point blank range with RPG like weapons or enemy mines, IED's and similar weapons can still be laid to deter mobility.

Collin, the Merkava is the conceptual idea to see how rearranging the internal layout of the tank could provide the means to carry a much larger weapon without expanding the armoured envelope or weight. A Gen 4 tank with a front mounted engine, clear rear area and robot turret could be built today from a PUMA chassis, for example, and the CVCT120 is a "light" version of this idea. It seems clear to me that the real "revolution" would be networking the tank into a larger sensor network so the tanker could "see" potential targets outside of LOS, and potentially engage (currently tanks could be in a target area but unable to engage because the target is not LOS).

Haligonian, the US Army wrote its pre WWII doctrine around that very idea and their Tank Destroyers of WWII were the embodiment of the idea, but the overall execution left something to be desired (to say the least).

 

[Colin Parkinson]

The US army has being toying with light tanks for years, the reality is that it is not willing to accept the loss rate that goes with them. The French did and the AMX 10-RC is really that a light tank without tracks. They gave up a little mobility for speed and minimal logistical footprint, but still retain the firepower. All light tanks sacrifice protection. I note the French are moving away from the big gun AC's to the auto cannon which is somewhat counter intuitive to the issues the Canadians ran into with their auto-cannons.
So far modern war has given us little tank vs tank since the Battle of 73 Eastings in the Gulf War, so the tank primary role will continue to be fire support for infantry with the ability to react to enemy armour.
We have tried oddball turrets far back as the M60A2 Starship, the MGS and the Jordanian Falcon Turret and I seem to recall the Swedes working on one as well. They seem to fall to the wayside. We have to see how the Armata does in real life with the commander having limited visibility to the rear. 

 

[daftandbarmy]

The US army has being toying with light tanks for years, the reality is that it is not willing to accept the loss rate that goes with them. The French did and the AMX 10-RC is really that a light tank without tracks. They gave up a little mobility for speed and minimal logistical footprint, but still retain the firepower. All light tanks sacrifice protection. I note the French are moving away from the big gun AC's to the auto cannon which is somewhat counter intuitive to the issues the Canadians ran into with their auto-cannons.
So far modern war has given us little tank vs tank since the Battle of 73 Eastings in the Gulf War, so the tank primary role will continue to be fire support for infantry with the ability to react to enemy armour.
We have tried oddball turrets far back as the M60A2 Starship, the MGS and the Jordanian Falcon Turret and I seem to recall the Swedes working on one as well. They seem to fall to the wayside. We have to see how the Armata does in real life with the commander having limited visibility to the rear.

The new 'light tank' is the IFV. The one thing that the last 15 years or so has confirmed about tanks, IMHO, is that the day of the MBT is not over... by a 'long shot' (forgive the pun ).

 

[George Wallace]

GR66, I'm thinking of the evolved gun tank as a vehicle which still needs protected mobility to survive on the modern battlefield. Enemy rounds will manage to "leak" through various countermeasures, brave or suicidal infantrymen could still pop up at point blank range with RPG like weapons or enemy mines, IED's and similar weapons can still be laid to deter mobility.

Collin, the Merkava is the conceptual idea to see how rearranging the internal layout of the tank could provide the means to carry a much larger weapon without expanding the armoured envelope or weight. A Gen 4 tank with a front mounted engine, clear rear area and robot turret could be built today from a PUMA chassis, for example, and the CVCT120 is a "light" version of this idea. It seems clear to me that the real "revolution" would be networking the tank into a larger sensor network so the tanker could "see" potential targets outside of LOS, and potentially engage (currently tanks could be in a target area but unable to engage because the target is not LOS).

Haligonian, the US Army wrote its pre WWII doctrine around that very idea and their Tank Destroyers of WWII were the embodiment of the idea, but the overall execution left something to be desired (to say the least).

Some serious design flaws with your premise here.  A tank requires good gun depression.  It is not going to get that with the turret anywhere back of the center line.  The further forward the gun, the better.  That way the tank does not have to go "tracks up" to shoot over hills, but it can instead use the hills as protection as it fires over them, exposing very little of the vehicle. 

Fuel tanks and engines placed in the front of the AFV work well in APCs and IFVs, giving them added protection for the crew and passengers, but that would be a poor design for a MBTs.

All AFVs are susceptible to IEDs.  As witnessed in Afghanistan, if two mines stacked would not kill an AFV, then three would be stacked, and then four.  It is always a game of "Catch Up" in providing armour protection, as it is always faster to produce a larger explosive to counter the armour protection.

In the 70's there was one philosophy that we saw in European AFVs like the Leopard 1 and the Mowag Piranha/AVGP/Cougar/Grizzly that was based on the 'Swiss Cheese Effect'.  The vehicles provided armour protection from small arms up to .50 Cal, and then were thin enough that larger rounds would pass straight through without ricocheting around inside the vehicle.  Armour protection was sacrificed for speed; which for a while provided protection, as most anti-armour weapons could not track vehicles that fast.  (Times have changed)  Speed and mobility were what was needed most. 

 

[a_majoor]

While I don't dispute the need to be able to depress the gun, George (it is also needed in an IFV as well), a tank or fire support vehicle which can engage with non LOS weapons provides the tank crew and the combat team commander with interesting new ways to defend or otherwise disrupt the enemy. Firing downhill at 2000m (assuming you have that clear field of view) is one thing, but skimming a top attack round over the enemy AFV, bunker or platoon in open 8 km away provides a much greater way to shape the battlespace.

Actually, I don't think the Merkava or CV90120 have issues when it comes to firing from defilade despite being front engine designs, so perhaps the issue isn't as severe as you might think. To be even more versatile, I'd actually advocate for something like the CV-CT turret, since it provides up to +420 elevation, allowing the crew to engage long range targets and shoot at annoying people perched on rooftops, win/win either way.

 

[NavyShooter]

Is it time to bring these into the picture yet:

http://bolo.wikia.com/wiki/Bolo_Mark_I

 

[Fishbone Jones]

Tanks can fire indirect, semi-indirect and direct. We don't need to see the target.

The max depression is dictated by the turret ceiling and the top of the breech.

If you want know the pros/cons with true light tanks, look at Chafees and Sheridans. Many things still apply

 

[George Wallace]

The max depression is dictated by the turret ceiling and the top of the breech.

This is true.  Why add to the limitations by having a long front end to the vehicle?  Remember what firing over the back deck limitations are on our current tanks.

 

[a_majoor]

Both the CV90120 and Merkava are reported to be able to depress the main gun 90. A cleft turret has no limitations to depression based on the turret roof (there is no roof over the breech).

The main issue is larger and larger guns, more and more armour etc. threaten to create immobile beasts rather than modern tanks. This issue was actually a factor in the cancellation of the "Block III" program back in the 1980's (the then projected replacement for the M1 was thought to weigh in at 80 tons), but this has historically derailed heavy tank and tank destroyer projects almost as long as there have been tanks (think things like the Char 2b, Maus, "Tortoise" or even the first generations of Chieftain tanks). Large and immobile platforms are no benefit to us and are just targets for the enemy to play with.

We are pretty much at the limit of how much extra performance you can squeeze from traditional designs, so it certainly is worth looking at the alternatives.

 

[MilEME09]

Both the CV90120 and Merkava are reported to be able to depress the main gun 90. A cleft turret has no limitations to depression based on the turret roof (there is no roof over the breech).

The main issue is larger and larger guns, more and more armour etc. threaten to create immobile beasts rather than modern tanks. This issue was actually a factor in the cancellation of the "Block III" program back in the 1980's (the then projected replacement for the M1 was thought to weigh in at 80 tons), but this has historically derailed heavy tank and tank destroyer projects almost as long as there have been tanks (think things like the Char 2b, Maus, "Tortoise" or even the first generations of Chieftain tanks). Large and immobile platforms are no benefit to us and are just targets for the enemy to play with.

We are pretty much at the limit of how much extra performance you can squeeze from traditional designs, so it certainly is worth looking at the alternatives.

I would say it's more likely we are at the limit of current building materials and armours, designs as well yes granted, western and eastern tank designs haven't changed much in the past 40 years. I would say the T-14 is the first break away from Russian tank design since the IS-3.

 

[GR66]

Are we getting to a point where larger numbers of light vehicles launching non-LOS weapons may be a better (and cheaper) solution than tanks in a defensive scenario where you have the luxury of being able to trade some ground to halt an enemy advance?  However, how effective are those light platforms in the advance when you have to expose yourself to enemy direct fire?  Or when you have to hold ground against an enemy advance?  Or in an insurgency where there is no clear front line?

Maybe the MBT still the best compromise solution until all the technological pieces come together to provide an all-around alternative. 

Could you maybe leaverage the excellent mobility, survivability and sensor capability of the MBT to take better advantage of new weapons?  Instead of a separate platform to launch your Non-LOS missiles use your tanks...something like was done in the past with unguided rockets.

 

[George Wallace]

When you start getting into vehicles that carry and fire a large number of NON-LOS munitions, then you are no longer talking about tanks.  You are talking more of anti-tank systems or MRLS artillery systems.

 

[Colin Parkinson]

I think any western army that can afford it needs a light and heavy brigade, with the appropriate supporting elements. Current history shows we will likely be defending Europe from Russia for the next 20 years. A potential to fight a sustained war in Korea for at least a decade. An ability to fight a organized but not near peer army somewhere in the world, conduct peace making and peace keeping around the world generally lined up against semi-organized forces along ethnic/religious and tribal lines. I don’t foresee any of those possibilities going away and never say never, imagine saying in the summer of 2000: “Canada will be in sustained combat in Afghanistan for a decade” You be laughed out of the room…. 

Going light and heavy, means you don’t have to compromise as much and generally the compromises suck. Yes it means having a more complex fleet, but better that than a fleet that is hopeless or inadequate for the task. The LAV would do well in most of Mali, the tanks would struggle. The reverse is true in Northern Europe.

 

[George Wallace]

What the Leopard 3 may look like and who will build it:

https://www.youtube.com/watch?time_continue=1&v=JNcnEPIfec8

 

[daftandbarmy]

I think any western army that can afford it needs a light and heavy brigade, with the appropriate supporting elements. Current history shows we will likely be defending Europe from Russia for the next 20 years. A potential to fight a sustained war in Korea for at least a decade. An ability to fight a organized but not near peer army somewhere in the world, conduct peace making and peace keeping around the world generally lined up against semi-organized forces along ethnic/religious and tribal lines.

And things like OP LENTUS which, apparently, can bring a military to its knees trying to sustain it at home over long periods of time.

 

[a_majoor]

I will have to disagree with George about merging tanks with NLOS weapons. This is already happening, for example Russian through tube missiles, the Israeli LAHAT through tube missile and the ROK's K-STAM top attack round. Many of these systems can actually be traced back conceptually to the Americans, for example the 1960 era MGM-51 Shillelagh anti-tank missile system, or the 1980 era TERM (Tank Extended Range Munitions) program.

The tank provides a powerful, heavily armoured and mobile fire support platform, while the combination of extended range and NLOS munitions combined with a high fidelity situational awareness allows the vehicles to engage targets in places and situations where conventional tanks cannot. A simple example is tanks in defilade cannot engage with APDFSF rounds, and using indirect fire with unguided HE or HEAT is inefficient and a waste of ammunition. Since a Korean K-2 can engage targets out to 8Km with K-STAM rounds, and Merkavas can engage at up to 13Km, the commander can use his armoured forces to shape the battlespace from a much greater distance. Since the firing platforms are tanks, they can also rapidly move to exploit the shaping, or retire if unsuccessful (more so than conventional or even SP artillery, for example).

Probably the greatest challenge for future tank designers will be how to get 40+ rounds into the tank in safe and efficient storage, but also easily accessible to the crew to engage a wide range of targets in a rapidly changing battlefield environment? If you can't carry sufficient main gun rounds, are there other ways to deal with this? I'll throw out one historic example: the Swedish Stridsvagn 2000 T140/40 was designed around a 140mm cannon to engage tanks, but carried a 40mm coaxial cannon to engage any lesser target (the thought being a 40mm would be able to deal with IFV's, bunkers etc. that presented themselves). Obviously there are other possible solutions to the problem, so it should be interesting to see how far "out of the box" new tank designers will go.

 

[Ostrozac]

And things like OP LENTUS which, apparently, can bring a military to its knees trying to sustain it at home over long periods of time.

Reports from France are that Op Sentinelle is seriously overstretching the French Army. If they want to maintain that level of troops on their streets, they may need a bigger army.

Similarly, the British Army had over 20,000 troops in Northern Ireland in the 70's, but that was with a bigger army, those levels would be difficult to sustain today.

Troops deployed are still troops deployed, whether it's a domestic or international operation, they aren't training and they aren't available for other tasks.