[Official] Armata Discussion thread #5

If diesel-electrics are really that good, then they ought to have replaced most diesel direct drives in low end torque applications a long time ago. Instead they are still relegated to niches involving very large platforms such as haul trucks for mining, and locomotives. Almost anything not involving hauling immense payloads across clear routes uses a mechanical transmission. This seems curious, since the mechanical transmission is the greatest source of failure in vehicles, and better yet, the electric motor displays superior acceleration performance at low speeds while consuming less fuel. It almost seems as if there are other considerations that give the edge to direct drives and make them far more usable than their hybrid cousins when it comes to certain tasks...

Requirements like high density of components. This one's pretty high up on the list if you're a tank and for good reason. Internal volume is at a premium for armored vehicles. A diesel-electric drive might not have a mechanical transmission but it has a bulky generator and motor set, plus the associated power electronics (necessary if you want to step up voltage and minimize ampere losses, at least) and cooling. A larger internal volume would see weight specs spiral up as you have to pile on more and more armor to maintain decent protection coverage. Its pretty telling that the Russians are considering an articulated design for their hybrid powered Armata successor - it effectively doubles the internal volume available to the vehicle while avoiding the penalties of overly long hulls. However if the same size is to be maintained, at some point it makes zero sense to go for a much efficient powerplant when an even smaller volume and weight of fuel could maintain the same range albeit much lossy. This passes the strain on your logistics but it does result in a much smaller and lighter vehicle, which in of itself poses massive advantages in other areas.

Another huge requirement is reliability. Mechanical transmissions are prone to failure, but most issues are readily fixable on the field. The technology is much more mature, and typically there are more people more familiar with mechanical issues than electrical ones. Hybrids in contrast are relatively immature technology with lots of teething yet to be resolved. The electric motors for example exhibit several failure modes that aren't necessarily found or as damaging in mechanical transmissions. There is a very real possibility for instance, that in case of strong transverse impacts on the suspension that the rotor could breach the tight armature gap and come into contact with the stator. Moisture is also a possible problem, especially since fording rivers is an essential capability and the hot windings can collect moisture from the air in cold and or humid environments.

Of course none of this means that the direct drive is to stay forever either. Eventually a much better technology would replace it, but if that is to happen the benefits must more than outweigh the cons for users to shift. Personally I'm betting on direct hydrocarbon fuel cells that combine the high energy density of hydrocarbon fuels with all the benefits of an electric drivetrain but that's just me. We'll just have to wait and see what will out eventually.

The T-90A turret on the T-14. From https://twitter.com/aviakurs:

Bonus:
Winter T-14 test:

Serial production of Armata tanks to begin before trials are over

https://tass.com/defense/1241181

mnztr wrote:Yeah I don't see them needing to produce more then 100-200/year as long as they keep modding the other tanks. They have an INSANELY huge fleet of tanks, like BATSHIT huge.

Modernized vehicles don't stay modern for very long. Eventually they would have to replace even the current crop of T-90M, T-80BVM and T-72B3 vehicles just entering service, and at this point the scope for cost effective improvements for these vehicles are all but tapped out. It would be silly to further invest taxpayer Rubles and UVZ factory space in increasingly expensive upgrades that approach the cost of mint designs and that would only prolong the competitiveness of the vehicles themselves for ever shorter periods of time like most countries in NATO are doing.