1- The 130 mm gun serves no purpose
Future tanks will have two main types of ammunition:
- kinetic energy penetrator (APFSDS) against armored targets
- programmable high explosive/fragmentation (HE-FRAG) round used against soft targets including lightly armored vehicles or helicopters.
Re. 1:
Mass is energy. Penetrators need sufficient kinetic energy to move their mass/energy through the mass/energy of armor. Kinetic energy is depleted with range. While the energy remains high for many kilometers it quickly becomes insufficient for penetrating through heavy armor. 10% energy loss over distance is sufficient to stop the round. Higher kinetic energy means that the margin for energy is higher, which will complicate design of passive armor which already put vehicle mass at 70t which is near practical use threshold.
According to Rheinmetall Rh-130 L51 has 50% higher kinetic energy compared to Rh-120 L44.
The biggest change between 120mm and 130mm guns is in the construction of the chamber which allows for longer casing but that would involve the re-design of the barrel to handle increased pressure. The work necessary for development of new construction would be wasted on 120mm because increasing caliber adds performance margins that are very advantageous.
Re. 2:
130mm round has ~0,53m2 cross-section and 0,816m circumference.
120mm has ~0,45m2 cross-section and 0,753m circumference.
This means 15% increase in cross-section area and volume for the round and 7,5% increase in surface area. Both parameters mean better explosive performance for programmable munitions and in particular better ability to shape explosions which is important for intelligent munitions with multiple use.
For APFSDS the main parameter is penetrator length and propellant charge. 120mm penetrators have recently reached technological limits so increasing caliber and overall round volume allows to improve performance which is better achieved with 130mm caliber compared to 120mm redesign. Tank armor and armor-piercing munitions are fields of extreme material science not very far from what is being done for hypersonics.
Finally Consider that the 130mm caliber is actually a
10mm reduction compared to the previously proposed 140mm gun which were under development in the US and France and were cancelled only because Soviet 4th gen MBTs which were a reaction to NATO 3rd gen MBTs never materialized. It is also only
5mm increase over 125mm guns used by Russian/Soviet and Chinese designs.
2- Their contribution to the battlefield is almost negligible compared to their cost
Bringing firepower to the battlefield is the role of artillery. Tanks bring
momentum necessary for
exploitation of breakthrough. Tanks are highly specialized weapons optimized for that mission. Everything else is incidental.
The main characteristic of the tank is not the firepower of a large caliber gun but mobility that enables an armored formation to maneuver on distances which are significant on a tactical, and sometimes even operational scale. Armor is a secondary characteristic so that the vehicle can withstand enemy fire allowing movement through defensive positions if necessary. The large gun is there only to make the maneuver faster. Think of the tank improvement over an armored APC towing a gun.
3- They don't solve the three fundamental problems that tanks are facing today
ATGMs are not magic. They have HEAT warheads which work according to specific physical process that can be countered by appropriate tank design.
HEAT produces a stream of molten metal that penetrates inside the tank damaging the crew and flammable materials. If the tank has good fire suppression solutions and design protects the crew an MBT can be penetrated by several HEAT warheads and continue fighting or withdraw from battlefield with minor damage. APFSDS use a different physical process that generates more damage inside the tank after penetration which is why tanks no longer use HEAT. ATGMs have no choice and are stuck with inferior armor-piercing technology because they need to be small and portable.
Then there's the question of ATGM hitting the tank which can carry a hard-kill active protection system and better active and passive camouflage than the ATGM team or their vehicle. ATGM has an IR signature that can be spotted by a 360-degree AI-enhanced observation system which deploys soft and hard-kill measures. Modern multi-spectral smoke screens effectively blind any optical guidance in ATGMs.
Don't forget that the ATGM has to destroy or immobilize the tank while the tank has to roll over enemy defense line. It doesn't have to destroy it because its target is the
rear of enemy forces.
The clips of ATGMs hitting the tank are selected for propaganda purposes from multiple hits that did not penetrate the armor and even more numerous misses. When the tanks are destroyed is when they are immobile and not using proper tactics. In Ukraine or Syria that was commonplace because of low skill levels of tank crews. The tanks with better crews and commanding officers are the ones that are not on those propaganda clips.
Tanks are also the most survivable vehicle including against artillery fire. Everything else is less survivable and requires fewer resources per artillery round to destroy or suppress. Tanks are by all metrics the hardest vehicle to kill on the battlefield provided they are properly used.
4- Loitering munitions on tanks make no sense
They are the single biggest game-changer. You just have to think like a tank commander sitting inside a tank and not a World of Tanks player.
Military operates along levels of command: tank - platoon - company - battalion - brigade/regiment. All levels have assigned objectives and resources and have different information about the battlefield. It's not even the fog of war as just different understanding and ability to convey what's happening up/down the chain of command.
When a tank platoon has an objective to take a town but recon reports that there are enemy tanks hiding behind buildings the tank/platoon commander has options:
- follow the objective and risk engaging unidentified enemy defense
- request additional recon to identify prepared enemy defense and avoid it
- request additional fire support to suppress unidentified enemy defense
- request additional recon and fire support to identify and suppress enemy defenses
These options are ordered in the degree to which they absorb time and resources at higher levels and the likelihood in which the request will be denied.
Having an organic UAV or loitering munition resolves 2, 3 and 4. A tank platoon of four tanks will have between 4 and 8 UAVs. That's enough for most tactical problems and might mean the difference between losing tanks and not. Combat is not a continuous process like in computer games. 95+ % of time it's moving between locations and waiting and 5+% is actual combat. This is why reduction in stored ammo turned out to not be that much of a problem as better FCS compensated for it.
I expect that over time tanks will become a highly survivable manned command node while all the recon and primary engagement will fall to unmanned systems - both UAV and UGV - and artillery with MBTs using their guns for exceptional situations like engaging another MBT on the move.
5- A tank can not defend against UAVs effectively
Autocannon RCWS is an universal small-caliber weapon with greater firepower than a 7,62mm or 12,7mm that will be used in built-up areas where tanks face threats at elevation and against threats that doen't warrant expending main gun munition. 20-30mm cartridge allows for programmable munitions.
The notion of "anti-aircraft machine gun" is a
historical naming convention. The main anti-aircraft weapon is an gun-launched missile or programmable HE-FRAG round while "AA" guns are primarily used against ground targets.
To sum up, I think these new tank concepts are tech development for the sake of tech development which is a problem that plagues the current European procurement. Extremely high-tech, extremely expensive but actually solve very few problems that the current tanks face.
Optionally Manned Tank follows the same design principles:
The design principles follow from those findings developed with the help of experienced tank crews.
