That's additional complexity the crew could do without.
It is nothing to do with the crew. In the Armata or Kurganets or Boomerang or Typhoon tank there wont even be any crew in the turret near the gun anyway...
Saying that will be a problem for the crew is like saying having backup power cables through the tank in case one power line gets cut by a penetration or battle damage will be a problem for the crew.... they likely will have no idea they are even there.
Aircraft have teams of maintenance crews working to keep everything up and running, while a tank only has one. Tank crews still need rest you know.
Formula one race car teams don't generally have a fuel line maintenance team that checks the fuel lines for cracks or damage after ever lap... most of the time fuel flow sensors and pressure sensors and other clues will tell the maintenance crew if there is something wrong and rather than using nano robots to crawl through the tubes they should be able to remove sections and replace them if there appears to be a leak in that section.
I am not suggesting it will be easy or trivial, but liquid propellent is already widely used for aircraft and motor vehicles for propulsion... they recently showed a truck that can pump fuel to about 24 aircraft at once.... imagine a similar vehicle that can arm 24 tanks at a time with propellent while the projectiles are being loaded...
Obviously it really comes down to the question... can they make the liquid propellent more powerful or more effective than solid propellent... it is certainly worth exploring just for the safety advantages.
The trick is its over-engineered for the kind of power contained in every ignition. Each explosion in an average motor vehicle is basically the work of one measly drop of gas so it won't ever reach more than a tiny fraction of allowable stress of the materials involved.
Firing missiles.... for which they have a special ejector that looks to me to just be a powerful spring, or HE rounds or HEAT rounds does not require max pressure max velocity. Obviously the variable propellent is vastly more useful for Coalition and of course Howitzers have always been using variable propellent charges because of the nature of how they are used, but in this case being able to vary propellent options might not be used except in the same sense that solid propellant is varied (ie extra for APFSDS rounds, less for the others).
The APFSDS rods are much lighter than the HE and HEAT rounds so clearly it accelerates faster and actually spends less time in the barrel...
Imagine being able to vary the mix of propellent components to better suit the different requirements.
To be clear I am not talking about infinite variability.
Think of it in terms of a swing wing fighter like the MiG-23.... it had three wing sweep options... a straight wing with no sweep that was used for takeoff and landing and medium speed ferrying flying long distances from one place to another. The fully swept back wing minimum drag for max speed flight at high and low altitude... at very low altitudes gave a much better ride than other aircraft with bigger wings and minimum drag meant max speed and max acceleration. And finally the half sweep which allowed speed but also best manouverability at combat speeds.
In the west it was criticised because it was not as sophisticated as the system on the F-14 and F-111 which used computer controlled continuously variable sweep to optimise the sweep for what ever the pilot was intending to so, but honestly I doubt the more complex western system was better.
I would trust the pilot to know what they intend to do and the set up meant they would never need to urgently change from one setting to another one... a high speed takeoff will always only ever use a straight wing, perhaps the pilot could then decide which sweep to go to depending on what they were going to do next, but it would be unlikely they would be constantly fiddling with the angle settings to get it perfect.
The liquid propellent system would help cool the barrel when it is pumped in, but the amount of fuel and composition might just be three different loads... a light one for launching missiles and drones, a medium one for HE and HEAT rounds, and a heavy charge for APFSDS rounds.
With experience they might find adding information from the ballistics computer based on the range of the shot could allow some variation in pressures, but obviously there will be max limits with a significant safety margin that it would never get close to and you could also have a venting system and sensors in the gun in case pressures get too high.
A special gun barrel that allows fuel to be pumped through it could be used to cool the barrel and also preheat the fuel... but you could have injection nozzles along the barrel to pump extra propellent behind the round as it travels down the barrel to help keep the pressure up... like those German long range guns with added propellent charges along the barrel that were fired as the round passed them to boost speed and range.
Direct warfare between industrialized states is rather rare these times - your point?
My point is that APFSDS rounds are not the main killer of tanks these days most of the time.
In many conflicts APFSDS rounds are not used very much... in fact I would think a decent APHE round should be developed and deployed for conflicts where the enemy does not have modern tanks.
The west is very pro APFSDS rounds and always has, but the Soviets actually produced a lot of HEAT rounds in the 70s and 80s and tended to use them more as a more multipurpose round.
They also tend to carry more HE rounds than the western tank forces do, and their BMPs also carry HE focused weapons like the 73mm gun of the BMP-1 and the 100mm rifled HE gun of the BMP-3.
Only really applicable against enemies with inadequate air defences very few armies today even have. But that is no reason to act like the status quo is never going to change either.
You mean like most of HATO... they barely have enough SAMs to shoot down Russian aircraft, but add drones and standoff missiles and they are in trouble.
Even when fully equipped with SAMs...
I think current nitrocellulose based propellants are what, 50 years old at least. There must have been developments in more effective propellants by this time.
The improvements in solid rocket fuel suggest as much.
A while back on a thread about small arms ammo propellant an expert from a Russian company said improvements in powder should allow an increase in muzzle velocity for most ammo types of about 30% without any changes to the fire arms, simply by improving burning rates and getting to pressure levels quickly in standard length barrels.
For the AK and AKM that means going from a 120 grain bullet moving at about 720m/s to a 120 grain bullet moving at about 930m/s... now that is a 7.62mm calibre round so aerodynamically it is not going to be as efficient as the Grendel round and other new rounds the west goes on about, so it wont have many of the range improvements the new smaller calibre variants would have, but it should flatten the trajectory quite a bit and increase energy of the round to do a bit more damage at the 200-300m range where it will be used.
The obvious drawback would be the iron sights will now be out, but getting extra velocity just increases the point blank range so leave the sights on 300m and aim for centre of mass.
To be clear introducing new tank gun propellent will be expensive and complex, but in an unmanned turret it could be as simple as having multiple propellent tanks around the vehicle acting as spaced armour that feed to the gun barrel... the different components might be mixed before going in to the chamber or mixed in chamber... I don't know... it might have enough propellent mixed for 4 to 5 shots ready to go so that if lots of enemy vehicles appear it can fire off those 4-5 shots quickly and while it is firing and using up propellent it can be mixing a new batch for 4-5 more shots so in effect it can fire continuously, but an enemy hit to the mixing container at worst will ignite only a small amount of propellent material that will not detonate like HE could and that could be vented upwards in a safe direction.
The venting design could allow the damaged tank to be removed and replaced and plumbed in with new roof mounted module that clicks into place.[/quote]
Last edited by GarryB on Wed May 19, 2021 4:08 am; edited 1 time in total (Reason for editing : fix broken quote)