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    T-90 Main Battle Tank #2

    lyle6
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    Post  lyle6 Wed Mar 31, 2021 2:05 pm

    T-90 with Burlak turret.
    T-90 Main Battle Tank #2 - Page 10 JrSskQ9
    T-90 Main Battle Tank #2 - Page 10 RPTrn0S

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    Post  GarryB Thu Apr 01, 2021 4:10 am

    Nice.

    The irony is that the rear turret bustle area for ammo is ideal for long rod penetrator rounds because of the available length and straight ramming the round and the propellent case, but on paper you really want to put your HE and HEAT rounds there so they are not under the crew.

    Of course putting your HE rounds there makes them more exposed and vulnerable to enemy fire, so having APFSDS rounds there makes most sense I guess.

    Any information on it?
    lyle6
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    Post  lyle6 Thu Apr 01, 2021 6:09 am

    The best resource thus far is the Baron, and these are what he wrote for the Burlak:
    http://btvt.info/2futureprojects/omsk_turret.htm
    https://btvtinfo.blogspot.com/2021/03/vs.html
    http://btvt.info/7english/640a/640.htm

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    Cyrus the great

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    Post  Cyrus the great Fri Apr 09, 2021 6:01 pm

    GarryB wrote:Nice.

    The irony is that the rear turret bustle area for ammo is ideal for long rod penetrator rounds because of the available length and straight ramming the round and the propellent case, but on paper you really want to put your HE and HEAT rounds there so they are not under the crew.

    Of course putting your HE rounds there makes them more exposed and vulnerable to enemy fire, so having APFSDS rounds there makes most sense I guess.

    Any information on it?

    Wouldn't it be possible to link an automatic impact sensor on the autoloader with 4 armoured vent-ports at the bottom of the hull that automatically open and redirect propellant explosions out of the tank? This could be similar to the spent shell casings port at the top of the T-90 turret but the vent-ports would be much thicker -- corresponding in armour thickness with the rest of the hull underside.  

    Automatic fire suppression systems work within milliseconds, so a system like this should deal quickly with propellant explosions very quickly. Doing all of this would remove the danger of propellent explosions inside the hull.

    http://www.army-guide.com/eng/article/article_3256.html

    Based on the article above, do you think that Russia should make 80mm + 80mm cuts to the sides of the hull and upgrade the autoloader in order to accommodate the 900mm Vaccum-1 APFSDS-T or should it just use the Burlak turret to hold longer sabot rounds?


    Last edited by Cyrus the great on Sat Apr 10, 2021 12:11 am; edited 2 times in total
    lyle6
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    Post  lyle6 Fri Apr 09, 2021 8:17 pm

    Cyrus the great wrote:

    Wouldn't it be possible to link the automatic fire suppression system with 4 armoured vent-ports at the bottom of the hull that automatically open and redirect propellant explosions out of the tank? This could be similar to the spent shell casings port at the top of the T-90 turret but the vent-ports would be much thicker -- corresponding in armour thickness with the rest of the hull underside.  

    Automatic fire suppression systems work within milliseconds, so it should quickly deal with propellant explosions. Doing all of this would remove the danger of propellent explosions inside the hull.

    The fire suppression systems aboard tanks utilize inert gases released at high pressure to displace the available oxygen in the crew compartment. It does nothing for propellant fires since those substances carry their own supply of oxygen to sustain the deflagration reaction. Not only that, it will knock and asphyxiate the crew in very short order if they aren't very quick on their feet and manage to pull themselves out of the hatch.

    Cyrus the great wrote:
    http://www.army-guide.com/eng/article/article_3256.html

    Based on the article above, do you think that Russia should make 80mm + 80mm cuts to the sides of the hull and upgrade the autoloader in order to accommodate the 900mm Vaccum-1 APFSDS-T or should it just use the Burlak turret to hold longer sabot rounds?  

    Neither. Both initiatives would have cost too much for very little gain in performance. The main issue with Russia's tank fleet isn't the relative weakness of their anti-tank weaponry or of their armor suite against the very latest NATO anti-tank weapons, its the lack of modern sensors and battle management systems. Without effective thermal sights your tanks would be at a very severe disadvantage when it comes to target acquisition and engagement, and in tank duels, its often the tank that gets the first shot off that wins the fight. Similarly, its always the force that has a much shorter OODA loop that prevails over one that doesn't. Incidentally, all the major tank modernization packages that were adopted have incorporated elements that significantly improve Russian tanks along these key parameters, with the T-14 pretty much perfecting the rest.
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    Post  Cyrus the great Fri Apr 09, 2021 9:18 pm

    lyle6

    I should have worded it differently so I made a slight edit to my post to reflect this; I meant to say that a system that automatically detects fires (especially in the autoloader) could be linked with underbelly port-vents to redirect propellant explosions out of the tank. Underbelly port-vents could be the equivalent to blow-off panels but they would not introduce weak  points in the armour.

    I know there is no fire suppression system that could possibly fight propellent explosions, so a sensor linked to the autoloader is what's needed.

    Perhaps it would be better to have an impact sensor on the autoloader; this sensor could be designed to react to the impact of a direct hit, so that a potential propellent explosion could be redirected out before it actuates and kills the crew.

    I was under the impression that the Svinets APFSDS-T is unable to penetrate Western tanks and that this is why the Vacuum-1 APFSDS-T was created. The T-14 Armata is the only tank that can accommodate this long round, so it would make sense for the T-90M to hold it in its arsenal.

    Sensors on the T-90M already seem very advanced and if there is any need for more advanced systems... the T-14 is available.


    Last edited by Cyrus the great on Fri Apr 09, 2021 10:34 pm; edited 1 time in total
    lyle6
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    Post  lyle6 Fri Apr 09, 2021 9:37 pm

    It wouldn't work either. The isolation would only really be effective if the geometry of the penetrating hit allows for trajectories that don't cross into the crew compartment at all. Because if they did, the pressure vessel would vent into the crew compartment instead. That's why the turret bustle ammo stowage only really protects against attacks from the sides, but not the front and rear. If you fire at an Abrams and manage to penetrate the thick turret front armor it would have the same result had it been a T-72 - a funeral pyre.

    And no, that's not really the case. Well, its true for the most modern variants of NATO tanks, but those are quite few in comparison the more numerous cold war legacy tanks, in which case the Svinets might as well be hot knife through butter. Those most modern NATO tanks have very poor mobilities as well, so its quite trivial to amass multiple lines of advancing armor and flank them outright.
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    Post  Cyrus the great Fri Apr 09, 2021 10:45 pm

    lyle6 wrote:It wouldn't work either. The isolation would only really be effective if the geometry of the penetrating hit allows for trajectories that don't cross into the crew compartment at all. Because if they did, the pressure vessel would vent into the crew compartment instead. That's why the turret bustle ammo stowage only really protects against attacks from the sides, but not the front and rear. If you fire at an Abrams and manage to penetrate the thick turret front armor it would have the same result had it been a T-72 - a funeral pyre.

    And no, that's not really the case. Well, its true for the most modern variants of NATO tanks, but those are quite few in comparison the more numerous cold war legacy tanks, in which case the Svinets might as well be hot knife through butter. Those most modern NATO tanks have very poor mobilities as well, so its quite trivial to amass multiple lines of advancing armor and flank them outright.

    Yes, but what are the chances of actually getting a direct hit on the carousel autoloader from the front? The carousel autoloader is placed very low in the tank -- making a direct hit nearly impossible.

    If your tank has been hit from the rear, then you're most likely dead. The frontal armour of the M1A2 Abrams (and all MBTs) is quite thick, so the crew is well protected from the front.

    Protecting the crew from side hits and the resultant cook-offs and explosions is a plus.
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    Post  lyle6 Sat Apr 10, 2021 6:57 am

    Cyrus the great wrote:
    Yes, but what are the chances of actually getting a direct hit on the carousel autoloader from the front? The carousel autoloader is placed very low in the tank -- making a direct hit nearly impossible.

    If your tank has been hit from the rear, then you're most likely dead. The frontal armour of the M1A2 Abrams (and all MBTs) is quite thick, so the crew is well protected from the front.

    Protecting the crew from side hits and the resultant cook-offs and explosions is a plus.

    Hits to the side would still stand a very good chance of puncturing the pressure vessel and venting the contents to the crew compartment. Any small cracks, gaps, or holes is enough for the crew to be roasted alive inside the tank. Speaking of, the carousel autoloaders have lots of gaps that expose the ammunition inside to the crew space. Really, the only solution is the one taken by the T-14 with full separation of the crew from the onboard incendiaries.
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    Post  Cyrus the great Sat Apr 10, 2021 8:21 am


    lyle6 wrote: Hits to the side would still stand a very good chance of puncturing the pressure vessel and venting the contents to the crew compartment. Any small cracks, gaps, or holes is enough for the crew to be roasted alive inside the tank. Speaking of, the carousel autoloaders have lots of gaps that expose the ammunition inside to the crew space. Really, the only solution is the one taken by the T-14 with full separation of the crew from the onboard incendiaries.

    I understand that there is still a chance that a direct hit to the carousel autoloader armour plate above would expose the crew to propellant explosions, however, the chances of that are very low.

    Like ERA and active protection sysyems, vent-ports would just be another tool to protect the crew by redirecting propellant explosions out of the tank in instances where the armour plate separating the crew and the autoloader hasn't been destroyed.

    A direct hit to the bulkhead separating the crew and ammunition in the M1A2 presents the same dangers to the crew. The T-14 Armata is in a league of its own but I suspect that Russia will still have uses for T-90M tanks.

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    Post  GarryB Sat Apr 10, 2021 10:33 am

    Wouldn't it be possible to link an automatic impact sensor on the autoloader with 4 armoured vent-ports at the bottom of the hull that automatically open and redirect propellant explosions out of the tank? This could be similar to the spent shell casings port at the top of the T-90 turret but the vent-ports would be much thicker -- corresponding in armour thickness with the rest of the hull underside.

    If you are referring to the hull mounted autoloader, the real problem is volume and speed.

    If you take a rifle bullet and pull the projectile and pour the propellent onto a flat surface like a table and then ignite it, you don't get the same detonation like explosion you get when the round is fired in a gun.

    The combustion conditions are different... the propellent will go fuff... there will be a flash and a lot of unburnt powder will be blown everywhere in a puff of smoke and flame.

    Open to the air the burning powder is not contained, there is not high pressure and heat to burn all the propellent grains fully, and the act of burning and therefore generating large volumes of gas, which is the purpose of propellent actually blows propellent away from the flames before they are properly lit so the ignition is slow and incomplete and actually rather disappointing.

    In a TV show or movie a rifle bullet dropped into a fire will explode and send the bullet at high speed and could kill someone.

    In the real world it would take a minute or two for the shell case to heat up to anything like the temperature needed to set off the powder... after firing a burst of 50 rounds in a machinegun the chamber is too hot to touch but rounds don't go off yet.

    A complete bullet dropped in the fire would have the same problem of propellent on the table, the shell case contains the propellent so pressure would rise as the powder burns but as soon as the bullet pops off the shell case the pressure drops again, so incomplete powder burn and no pressure... the shell case and primer are lighter than the bullet normally so rather than a bullet flying out of the fire, what you would find is the projectile sitting almost exactly where it landed and the shell case a few centimetres away where it was blown to by the pop of the propellent burning.

    In comparison a tank hull is a big container that is largely closed off, and the propellent from 22 rounds of ammo... even if they are not HE rounds is an enormous volume of stored gas in a vessel that could achieve enormous pressures if it all went off at once. APFSDS don't contain HE but have a lot more propellent in a tank equipped with a 125mm gun.

    The propellent in the 125mm rounds is protected from damage by a small metal stub and propellent impregnated cardboard that is consumed when the round is fired... hot sparks or flame will ignite it immediately.

    Fire suppression systems will stop material like rubber or fuel or plastics from burning by taking away the oxygen.

    Propellent contains enough oxygen mixed together with fuel to burn the fuel so fire retardant... even water... wont stop it once it starts burning, and being in a contained space with lots and lots of propellent, it is never going to end well.

    The real problem is if there is HE there as well... if you burn HE then it burns... HE is not called high explosive because it is more powerful than a low explosive.

    The high and low refer to the sensitivity of the explosive, so high explosive is insensitive and needs an explosion to set it off... to make it explode.

    Nitroglycerine is a low explosive... its components are highly reactive and highly unstable... shake the bottle violently and it will explode.

    You could hit modern plastic explosive with a hammer or set it on fire and it wont explode.

    To make the explosive explode on target however, you need a fuse, which contains a complex mechanism that will set off a low explosive charge when the round impacts a target, but wont set it off at the shock of being fired, or hitting rain drops on the way to the target, or some idiot dropping the round before it has been fired.

    Note most fuses are designed so the round has to undergo high g acceleration before the safety is disabled so if you drop the shell on its nose while loading it it wont go boom.

    An RPG-7 grenade does not have such a sophisticated fuse so if you take the fuse safety cap off and drop it... it will go boom.

    The point is that the fire that burns all the propellent in a turret magazine will often set off the low explosive charges in HE and HEAT rounds.

    Like the bullet in the fire it will take time for the heat to reach the low explosive so the turret might burn for a few minutes, but when one HE or HEAT round explodes the containment of the explosion inside the vehicle makes it many many times more powerful than any explosion outside the vehicle so any other HE round will likely explode too... when they all explode it is an explosion... not propellent burning... explosions are supersonic and the tank will be shattered.

    A propellent fire will often blow the turret up and off the tank... pressure will take the line of least resistance and the turret is the cork on a bottle.

    When HE rounds explode the cork might remain on the bottle but the body of the bottle will shatter into an enormous number of pieces.

    Blow out doors help release pressure so the propellent does not burn fully, but blow out doors mean nothing to an explosion of HE and HEAT rounds.

    The Russians often carry rather more HE round than western countries because the know from experience tanks tend to meet non tank targets in real combat.

    In WWII a T-34 would only rarely if ever meet a Panther or Tiger, so having a 76.2mm gun with a good HE round made more sense than the 57mm ZIS-3 gun that could have penetrated either the Panther or Tiger from the front.

    Automatic fire suppression systems work within milliseconds,

    Automatic fire suppression systems activate in miliseconds, but if the propellent is ignited its chances of stopping an eruption of flames and heat is close to zero.

    so a system like this should deal quickly with propellant explosions very quickly. Doing all of this would remove the danger of propellent explosions inside the hull.

    Essentially you can't... the best you can manage is to place the propellent apart from the crew like in the Armata. Place it down in the bottom of the hull where it is harder to hit... the floor autoloader in the T-64 and T-80 proved vulnerable because the propellent charges are not protected... a turret or hull penetration that filled the internal compartment with sparks and shards of hot metal and flames would often set off the propellent charges in the autoloader setting a near instant chain reaction of 28 propellent stubs going off at once and blowing the turret off the tank. The T-72 and T-90 were better off because it stores 22 rounds in the same place but it is under a layer of light armour so sparks can't land on combustible cardboard propellent stubs.

    That is not to say the T-72 or T-90 are perfect and with any tank when a fire starts you get out fast because within a few minutes the ammo will cook off and the turret will blow off most of the time... just like on most tanks with ammo.

    The M1 Abrams is no safer... an RPG7 shot with an ancient rocket to the turret bustle will set off the ammo too and when it all goes off the crew are in no better situation than in any other tank.

    Penetrations into the hull or turret often result in explosions when fire reaches ammo stored in the turret or the hull.

    The much better performance of the T-72s in the second Chechen conflict was because they only carried ammo in the underfloor autoloader, so penetrations of the armour were not catastrophic because they might hit a crewman, but would not lead to the whole vehicle being destroyed.

    The T-90AM has 22 rounds of ammo in the autoloader under the turret, a further 8 rounds between the turret bustle and the engine, and the remaining 12 rounds in a turret bustle that is not connected to the turret internally.

    That means if you hit the turret bustle there are only 12 rounds in a large area so unlikely to all explode, the underfloor autoloader needs a direct hit to set off ammo inside it and the ammo between the engine and autoloader are just as difficult to reach. Hull or turret penetrations that do not directly hit the autoloader under the turret or go through the turret bustle will not cause an explosion, which makes them much safer to operate.

    Having underfloor blow out doors probably would not help, but would likely make the vehicle more vulnerable to mines.

    Based on the article above, do you think that Russia should make 80mm + 80mm cuts to the sides of the hull and upgrade the autoloader in order to accommodate the 900mm Vaccum-1 APFSDS-T or should it just use the Burlak turret to hold longer sabot rounds?

    AFAIK they already did the former.

    Underbelly port-vents could be the equivalent to blow-off panels but they would not introduce weak points in the armour.

    Even with blow out panels a hit by a Konkurs ATGM led to an Abrams burning out when hit in the turret bustle... the blow out panels made no difference and did not save the vehicle. The bustle burned for quite some time and set fire to the engine compartment and the whole vehicle burned out... a total loss.

    Engine and propellent fires are not something you can put out in ideal situations let alone in view of the enemy or under fire.

    The crew jumps out and makes for friendlies and the tank is abandoned.

    In this case it burned out but if just lost a track or two then it might be bombed or a larger force sent to take control of the area while the disabled vehicle is towed... and I don't mean hit with a TOW.

    I know there is no fire suppression system that could possibly fight propellent explosions, so a sensor linked to the autoloader is what's needed.

    With Burlak a sensor that detects a penetration and fire in the turret bustle autoloader could be used to eject the turret bustle and prevent a fire destroying the tank, but the same would not work with an underfloor autoloader.

    Perhaps it would be better to have an impact sensor on the autoloader; this sensor could be designed to react to the impact of a direct hit, so that a potential propellent explosion could be redirected out before it actuates and kills the crew.

    The best solution is T-14... complete separation of the crew from the ammo and auto loaders.

    You could fill the entire hull and turret but not the crew compartment with nitrogen to displace the air so sparks would not burn... but as mentioned even a red hot piece of metal in the turret wont set flammable materials like wood or plastic or fabric on fire in a nitrogen gas filled space, but if that red hot piece of metal hits the cardboard propellent case of a 125mm shell... boom.

    I was under the impression that the Svinets APFSDS-T is unable to penetrate Western tanks and that this is why the Vacuum-1 APFSDS-T was created. The T-14 Armata is the only tank that can accommodate this long round, so it would make sense for the T-90M to hold it in its arsenal.

    They are developing all sorts of new ammo including new guided top attack missiles.

    It is my understanding that part of the T-90AM design is to allow it to use long rod penetrators...

    Yes, but what are the chances of actually getting a direct hit on the carousel autoloader from the front? The carousel autoloader is placed very low in the tank -- making a direct hit nearly impossible.

    That is the point, that it why it is located there...

    It is also why tanks have their thickest armour on their turret cheeks... because that it where many hits occur...

    If your tank has been hit from the rear, then you're most likely dead. The frontal armour of the M1A2 Abrams (and all MBTs) is quite thick, so the crew is well protected from the front.

    There are weak spots and exceptions on every tank... and a squadron of tanks will... even if all moving together in the same direction will have their turrets pointed in different directions looking all round for threats, so three out of every platoon of four tanks will be presenting turret sides or its rear turret...

    Planning ambushes is all about positioning.... put some signs indicating land mines in a field... indicate clear paths at intervals along the field to channel and limit the enemy vehicles. You don't even have to have any mines but if you do put them down each side of the channels... once the enemy forces arrive at the mine signs they will turn sideways and travel to find a lane to drive through... the first 20-30m you could put real mines incase some smartarse wants to test the signs... down the lanes put mines on either side so they will reach the lane and drive down it... once they are driving down the lane fire at the front and last tank with missiles... the tanks in the middle will be trapped... if they try to turn and leave the mines will get them.

    Taking out a group of tanks with some mines and two ATGMs...

    With a real mine field that is unmarked when they start losing tanks they will stop and turn and try to drive around the field... which presents the sides of the tanks for ATGM and RPG attack...

    When you don't know where the enemy is... how do you keep your front tank armour pointed at them?

    Unless you are driving right at them... you can't... and even if you are they just need to wait and let you drive past and shoot you up the arse at short range with an RPG-7 or other light weapon.

    Russian forces have more anti armour weapons than the rest of the world combined...

    Protecting the crew from side hits and the resultant cook-offs and explosions is a plus.

    Experience has shown that the armoured autoloader of the T-72/90 tank and not carrying ammo loose in the turret or next to the driver offers good protection from cookoffs and explosions.

    The ideal solution of course is the T-14.

    Speaking of, the carousel autoloaders have lots of gaps that expose the ammunition inside to the crew space. Really, the only solution is the one taken by the T-14 with full separation of the crew from the onboard incendiaries.

    The T-64/80 autoloader exposed the propellent charges to sparks and fragments if the turret was hit, the T-72/90 autoloader has a sheet metal shield to separate the combustible cardboard propellent stubs from sparks and fragments and fires.

    Obviously a turret penetration or hull penetration that starts a fire... the crew would bail... the fire would eventually hit the ammo and up she goes, but not instant like if you had ammo stored in the hull or loose in the turret and the outer skin is penetrated.

    A direct hit to the bulkhead separating the crew and ammunition in the M1A2 presents the same dangers to the crew. The T-14 Armata is in a league of its own but I suspect that Russia will still have uses for T-90M tanks.

    Developments in propellent could lead to a situation where it needs to be microwaved to actually burn, in which case it would be much safer to store in the crew compartment...

    I think I have mentioned to you in the past about the potential for binary propellents where the propellent is split into two separate liquids... on their own they don't even burn... they can be stored separately in the vehicle, but only when they are mixed together in the gun chamber and perhaps microwaved do they become highly flammable and effective as a propellent.

    The liquid could be stored in the space between armour layers and used as armour... you might not want to drink the stuff but it would not explode or even burn on its own.

    You could then use precise pumps together with ballistic computers to determine a precise propellent charge... for some targets you could reduce the propellent... especially for HE and HEAT rounds that don't rely on speed, while sometimes a bit of extra juice might be useful...
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    Post  Cyrus the great Wed Apr 14, 2021 6:33 pm

    Garry B

    Thanks a million for the breadth of information you've provided. I don't have the comparable knowledge to give an adequately informed response to most of what you've written.


    Garry B wrote: The much better performance of the T-72s in the second Chechen conflict was because they only carried ammo in the underfloor autoloader, so penetrations of the armour were not catastrophic because they might hit a crewman, but would not lead to the whole vehicle being destroyed.

    The T-90AM has 22 rounds of ammo in the autoloader under the turret, a further 8 rounds between the turret bustle and the engine, and the remaining 12 rounds in a turret bustle that is not connected to the turret internally.

    That means if you hit the turret bustle there are only 12 rounds in a large area so unlikely to all explode, the underfloor autoloader needs a direct hit to set off ammo inside it and the ammo between the engine and autoloader are just as difficult to reach. Hull or turret penetrations that do not directly hit the autoloader under the turret or go through the turret bustle will not cause an explosion, which makes them much safer to operate.



    The placement of the ammunition in the underfloor of the tank is ingenious; it's virtually impossible to reach in frontal attacks and can only be hit from the sides.

    The carousel autoloader seems to be a little over a meter off the ground; the distribution of probable attack directions graph shows that this area is only hit 2% of the time; areas in the middle are hit 33% of the time; areas around the turret area are hit 65% of the time.

    The safety of the carousel autoloader is further enhanced because it's mostly covered by the wheels of the tank with only 10 cm being above the tank wheels.

    I want to preface this by saying that my question might be incredibly stupid ... but why weren't the tank wheels made 10 cm higher in order to completely cover the carousel autoloader?

    I don't expect tank wheels to provide a substantial amount of protection, however, it is yet another layer of protection.

    Based on every page on specs, the T-90M turret bustle seems to hold 10 rather than 12 rounds.

    Garry B wrote:Having underfloor blow out doors probably would not help, but would likely make the vehicle more vulnerable to mines.
       


    The T-90M has an underfloor escape hatch and I imagine that it's well armoured; its armour protection is likely thicker than the surrounding bottom hull armour in order to compensate for the fact that its essentially a door. Perhaps I'm wrong, but couldn't 4 equally armoured automatic vent-doors be installed in the tank without weakening the armour?

    I wouldn't expect this to deal with the detonation of HE and HEAT rounds; it would only deal with propellant explosions.

    Garry B wrote: AFAIK they already did the former.    

    So the T-90M proryv-3 can accommodate the 900mm APFSDS-T rounds now? It's beyond awesome if that's the case. The Svinets are around 740mm long, so they're not quite as powerful. The Svinets still penetrates around 700mm of armour at 2000m so it's comparable to Western analogues.

    Garry B wrote: Even with blow out panels a hit by a Konkurs ATGM led to an Abrams burning out when hit in the turret bustle... the blow out panels made no difference and did not save the vehicle. The bustle burned for quite some time and set fire to the engine compartment and the whole vehicle burned out... a total loss.

    Engine and propellent fires are not something you can put out in ideal situations let alone in view of the enemy or under fire.

    The crew jumps out and makes for friendlies and the tank is abandoned.

    In this case it burned out but if just lost a track or two then it might be bombed or a larger force sent to take control of the area while the disabled vehicle is towed... and I don't mean hit with a TOW.  

    Yes, but the M1a2 Abrams has a gargantuan turret bustle that is so much easier to target and hit; 65% of probable attack directions are around the turret area.

    The carousel autoloader would be covered by terrain and the tank wheels of the T-90.

    Garry B wrote:  With Burlak a sensor that detects a penetration and fire in the turret bustle autoloader could be used to eject the turret bustle and prevent a fire destroying the tank, but the same would not work with an underfloor autoloader.
     

    The ejection feature would be a tremendous leap in crew protection. Why don't the Americans introduce something similar to this? The current blow-out panels don't seem that safe. Even if the turret bustle explosions and fires are re-directed outward.. the engine, turret and electronics would be damaged from a prolonged fire.

    Garry B wrote: The best solution is T-14... complete separation of the crew from the ammo and auto loaders.

    You could fill the entire hull and turret but not the crew compartment with nitrogen to displace the air so sparks would not burn... but as mentioned even a red hot piece of metal in the turret wont set flammable materials like wood or plastic or fabric on fire in a nitrogen gas filled space, but if that red hot piece of metal hits the cardboard propellent case of a 125mm shell... boom.  

    The crew protection features of the T-14 are most definitely in a whole different league.  I particularly like the fact that there is around 1 meter of armour separating the crew from the ammunition. The most effective (and toxic) fire extinguishers can be used without any concern that it will harm the crew.

    Garry B wrote: They are developing all sorts of new ammo including new guided top attack missiles.

    It is my understanding that part of the T-90AM design is to allow it to use long rod penetrators...
       

    I sincerely hope that the Vacuum-1 APFSDS-T is included in the T-90M; making the necessary modifications to accommodate this powerful APFSDS-T would obviate the need to have a larger (and more exposed) turret like the Burlak.

    Based on what you've written in another post, the Burlak has 22 rounds in the turret bustle, however, this introduces the turret overhang problems that plague Western tanks. The turret is statistically so much more exposed to enemy fire, so it makes sense to keep as much of the ammunition in the hull.

    Do you think that the Russians will eventually modify the T-90M in such a way that the crew can access the rounds in the turret bustle?

    Garry B wrote:  There are weak spots and exceptions on every tank... and a squadron of tanks will... even if all moving together in the same direction will have their turrets pointed in different directions looking all round for threats, so three out of every platoon of four tanks will be presenting turret sides or its rear turret...

    Planning ambushes is all about positioning.... put some signs indicating land mines in a field... indicate clear paths at intervals along the field to channel and limit the enemy vehicles. You don't even have to have any mines but if you do put them down each side of the channels... once the enemy forces arrive at the mine signs they will turn sideways and travel to find a lane to drive through... the first 20-30m you could put real mines incase some smartarse wants to test the signs... down the lanes put mines on either side so they will reach the lane and drive down it... once they are driving down the lane fire at the front and last tank with missiles... the tanks in the middle will be trapped... if they try to turn and leave the mines will get them.

    Taking out a group of tanks with some mines and two ATGMs...

    With a real mine field that is unmarked when they start losing tanks they will stop and turn and try to drive around the field... which presents the sides of the tanks for ATGM and RPG attack...

    When you don't know where the enemy is... how do you keep your front tank armour pointed at them?

    Unless you are driving right at them... you can't... and even if you are they just need to wait and let you drive past and shoot you up the arse at short range with an RPG-7 or other light weapon.

    Russian forces have more anti armour weapons than the rest of the world combined...  

    The introduction and use of drones for tanks and armoured units could provide greater protection against anti-tank teams.

    The ability to eject burning turret bustles would protect the crew and allow them to then use ammunition in the carousel autoloader to deal with the attacking concealed infantry and anti-tank teams.

    What you've written regarding ambush tactics reminds me of what I've read about the tactics employed by the Mongols. The "golden horde" left openings for their enemies to use once it was clear that the enemy was defeated; the enemy troops would then 'escape' through the openings provided for them only to find that they were being led to slaughter.

    Garry B wrote: Experience has shown that the armoured autoloader of the T-72/90 tank and not carrying ammo loose in the turret or next to the driver offers good protection from cookoffs and explosions.

    The ideal solution of course is the T-14.

    And it's going to be improved by adding APS and multiple layers of NERA and ERA on the sides. Relikt could be used to cover the base armour; NERA would be added next and 4S23/4S24 bags could be added as the final layer of protection. Cage armour might also play a role.

    Garry B wrote: Developments in propellent could lead to a situation where it needs to be microwaved to actually burn, in which case it would be much safer to store in the crew compartment...

    I think I have mentioned to you in the past about the potential for binary propellents where the propellent is split into two separate liquids... on their own they don't even burn... they can be stored separately in the vehicle, but only when they are mixed together in the gun chamber and perhaps microwaved do they become highly flammable and effective as a propellent.

    The liquid could be stored in the space between armour layers and used as armour... you might not want to drink the stuff but it would not explode or even burn on its own.

    You could then use precise pumps together with ballistic computers to determine a precise propellent charge... for some targets you could reduce the propellent... especially for HE and HEAT rounds that don't rely on speed, while sometimes a bit of extra juice might be useful...  

    The introduction of binary liquid and gel propellants would be a game changer. It might be possible in 15 years from now once we figure out the appropriate oxidizers and the reliability of the system in fast paced war conditions. The mix of the components would have to be consistent and durable enough to weather the rigours of war.

    A T-90 variant with liquid or gel propellants would allow the carousel autoloader to be modified to hold 44 rounds instead of 22 as the propellent would be elsewhere; the turret of the T-90M would never have to get any bigger and there would be no need for the larger Burlak turret. I actually like the small turret of the T-90a because it seems so much harder to hit.

    You kindly introduced me to and educated me on binary liquid propellants and their many advantages. I remember that conversation.
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    Post  GarryB Thu Apr 15, 2021 2:51 pm

    The placement of the ammunition in the underfloor of the tank is ingenious; it's virtually impossible to reach in frontal attacks and can only be hit from the sides.

    They have been designing tanks for some time now and have gathered a lot of experience and knowledge on the subject.

    There is no perfectly safe place to put ammo or fuel because once the enemy knows where it is they will try to target it, but the location they have chosen is much better than the back of the turret exposed to enemy fire from everything from ancient RPG rockets to BMP autocannon...

    I want to preface this by saying that my question might be incredibly stupid ... but why weren't the tank wheels made 10 cm higher in order to completely cover the carousel autoloader?

    They have played around with tank wheel size for some time... the T-72 wheels are a different size from the T-80/64, but the newer ones are made of aluminium and likely would not provide much actual kinetic or chemical defence from a hit.

    A better solution is the side skirts with ERA mounted on them.

    And of course keep moving.

    Based on every page on specs, the T-90M turret bustle seems to hold 10 rather than 12 rounds.

    I may be mistaken... I didn't check the numbers before stating them... are the numbers for the M and AM the same?

    The T-90M has an underfloor escape hatch and I imagine that it's well armoured; its armour protection is likely thicker than the surrounding bottom hull armour in order to compensate for the fact that its essentially a door. Perhaps I'm wrong, but couldn't 4 equally armoured automatic vent-doors be installed in the tank without weakening the armour?

    There is no firewall between the autoloader and the crew compartment, so even if there is blow out doors in the sides and bottom and above, the internal container that is the tank hull and turret will fill up with burning propellent before the pressure builds enough to blow out any blow out panels which would effectively incinerate the crew... or at least suffocate them.

    Leaving the crew hatches unlatched would achieve the same effect as blow out doors in terms of relieving pressure, but the results would likely be the same.

    I wouldn't expect this to deal with the detonation of HE and HEAT rounds; it would only deal with propellant explosions.

    If you look at the muzzle flash when the main gun is fired... that is one propellent charge. Several... up to 22 charges going off would create an enormous fire ball... blow out panels and hatches not on latches might prevent the turret being blown off, but there would be no survivors amongst the crew in such a situation.

    So the T-90M proryv-3 can accommodate the 900mm APFSDS-T rounds now?

    I would think it would be a priority for it to be able to fire their best rounds.

    It does not mention the rounds length but in the video below it shows them firing on a target 5km away getting direct hits in the centre of mass:



    Even with a shot fired on the move.


    Yes, but the M1a2 Abrams has a gargantuan turret bustle that is so much easier to target and hit; 65% of probable attack directions are around the turret area.

    It did rather well in Desert Storm because I suspect Americas enemies had not clicked to that being a weak point and something to aim at. Later conflicts in the region the Abrams did not do so well and quite a few were disabled.

    It still did rather well in terms of keeping its crew alive, but then with the T-72 and T-90 they got the same result when they stopped carrying extra ammo in the crew compartment too.

    Why don't the Americans introduce something similar to this?

    It makes more sense with an automated autoloader being attached like a rifle magazine means ejecting the magazine making sense too.

    The current blow-out panels don't seem that safe.

    The blow out panels are not a stupid idea... they are just not the perfect super solution some fan boys believe them to be.

    Even if the turret bustle explosions and fires are re-directed outward.. the engine, turret and electronics would be damaged from a prolonged fire.

    What would happen on a real battlefield is that a penetrating hit that starts a fire that the crew can't deal with would lead to the crew bailing out.

    If the tank continues to burn odds are good that fuel and ammo will eventually result in an explosion that will destroy the vehicle, but in some ways that prevents it falling into the hands of the enemy so it is not a bad thing as such.

    Ideally you want the vehicle to not burn and be able to drive back to friendly territory, but sometimes the location of the hits make that impossible.

    Number one priority is keep the crew alive and allow them to get out and escape.

    You can't ask much more from a tank.

    The crew protection features of the T-14 are most definitely in a whole different league. I particularly like the fact that there is around 1 meter of armour separating the crew from the ammunition. The most effective (and toxic) fire extinguishers can be used without any concern that it will harm the crew.

    In fact during combat the tank gun fumes can be stored in the turret and ammo compartment to reduce the risk of fire... anything like plastic or wood or synthetic materials that could burn would not burn without air. Obviously red hot metal fragments or sparks landing on propellent stubs will still set them off, but they will be separated with sheet metal protection to limit that chance.

    Based on what you've written in another post, the Burlak has 22 rounds in the turret bustle, however, this introduces the turret overhang problems that plague Western tanks. The turret is statistically so much more exposed to enemy fire, so it makes sense to keep as much of the ammunition in the hull.

    As I said AFAIK that was why the Burlak and Black Eagle designs were rejected at the time.

    Having ten rounds all spaced out and isolated just stored there with no way into the turret allows ten rounds to be carried with much less risk to the crew.

    Do you think that the Russians will eventually modify the T-90M in such a way that the crew can access the rounds in the turret bustle?

    The only way at the moment is to leave the turret and open roof hatches in the bustle I believe.

    Having an autoloader in the bustle means the bustle could be isolated with an armoured door and cover, the same way the carousel underfloor autoloader has armour plate separating the vulnerable propellent stubs from the crew compartment in case there is a penetration in combat.

    The introduction and use of drones for tanks and armoured units could provide greater protection against anti-tank teams.

    Drones would be good for better situational awareness, but as seen on the video above the wind sensor mast seems to have 360 degree cameras for SA for the commander...

    Later on adding an APS system as well will further improve protection.

    The ARENA APS system could be manually fired to engage enemy infantry approaching the tank.


    And it's going to be improved by adding APS and multiple layers of NERA and ERA on the sides. Relikt could be used to cover the base armour; NERA would be added next and 4S23/4S24 bags could be added as the final layer of protection. Cage armour might also play a role.

    It is what I like about Russian tank design. The US got composite armour designs from the UK and just used lots of that to make a 65-70 ton tank, which is not a bad tank, but by using multiple different soltions including composite armour and ERA and NERA and APS and Shtora type EW systems and cage/slat armour, and nakidka IR and radar fabric covers, they end up with a tank that is as good but 20 tons lighter.

    A T-90 variant with liquid or gel propellants would allow the carousel autoloader to be modified to hold 44 rounds instead of 22 as the propellent would be elsewhere; the turret of the T-90M would never have to get any bigger and there would be no need for the larger Burlak turret. I actually like the small turret of the T-90a because it seems so much harder to hit.

    With a binary propellent the entire rear turret bustle could be cells of one component of the propellent, while the front hull armour could have a large spaced cavity with the other propellent component... pumped back to the turret and both combining only in the gun breach, they could act as armour protection...

    You kindly introduced me to and educated me on binary liquid propellants and their many advantages. I remember that conversation.

    It is a very clever idea and interesting in terms of safety too.

    For them to be dangerous they need to be combined, so imagine a gel shirt that goes under your body armour and acts to reduce trauma of near penetrations, that has a tube that you attach to the butt of your rifle to "fill it", while another tube from a set of gel pants that protects your legs from blunt trauma that you attach to the front furniture of the rifle. Your ammo magazine contains projectile sized projectiles only and the internal pump system move the propellent components into the chamber of the rifle as needed...

    Ammo in the form of projectiles would be totally inert and therefore totally safe, while each propellent shipment will be separate and therefore inert too and not vulnerable to enemy fire except leaking onto the ground.

    You could take ammo forward in bottles or tanks or fuel bladder type reservoirs. Keep the two apart and they are totally safe... though I would not drink either of them...
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    Post  Hole Fri Apr 30, 2021 12:29 pm

    T-90 Main Battle Tank #2 - Page 10 E0k15k10
    T-90 Main Battle Tank #2 - Page 10 E0k16q10

    GarryB, franco, medo, George1, dino00, magnumcromagnon, Big_Gazza and like this post

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    Post  GarryB Sat May 01, 2021 6:46 am

    Good to see the commanders machine gun is a Kord and not a rifle calibre weapon.

    With the stabilisation and optics it should be rather effective at extended ranges but also devastating at short range too.
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    Post  lyle6 Sun May 02, 2021 10:56 pm

    Regarding binary/liquid propellants:

    Post battle damage survivability is just one aspect of safety and is strictly secondary compared to reliable operation of the main armament in this regard. Unlike conventional solid propellant guns, liquid/binary propellant guns have unsolved issues related to the predictability of the ignition process, leading to unplanned levels of stress incurred on the internal workings of the weapon, which could then lead for catastrophic failure. This is  unacceptable for current standards held by solid propellants, let alone further developments like the surface coated double base propellant as used in the DM-63 APFSDS.

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    Post  GarryB Mon May 03, 2021 6:57 am

    The potential makes it worth pursuing...
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    Post  lyle6 Mon May 03, 2021 9:20 am

    GarryB wrote:The potential makes it worth pursuing...

    The implementation of which would require vast sums just to setup the industrial infrastructure to support the logistics of this entirely new gun technology. New standards for storage, handling, and utilization would have to be developed that would only take further time, manpower and money. The amount of resources this technology would require to bring it to fruition would dwarf whatever tangible benefits it could bring. It was interesting for a time, when nobody was really certain what would it take to take down the next Soviet/Western supertanks, but 3 decades of sequestrations that forced investments in incremental improvements over every aspect of the gun system have shown that remarkable improvements are still possible even without resorting to exotica.
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    Post  Tingsay Thu May 06, 2021 2:26 am

    lyle6 wrote:T-90 with Burlak turret.
    T-90 Main Battle Tank #2 - Page 10 JrSskQ9
    T-90 Main Battle Tank #2 - Page 10 RPTrn0S



    Lol wow. Possibly the most aesthetic tank in the world in my eyes. This is how I always envisioned tanks, not handsome and clean(abrams, armata, challenger) but ugly, brutish and scary( t-72, merkava 3). Cool
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    Post  GarryB Thu May 06, 2021 8:23 am

    The implementation of which would require vast sums just to setup the industrial infrastructure to support the logistics of this entirely new gun technology.

    New tank guns are not cheap to begin with.

    New standards for storage, handling, and utilization would have to be developed that would only take further time, manpower and money.

    Handling and storage for binary propellants would be much safer than with any solid propellent.

    Pumping fluids into a tank would be much faster and easier and safer than hand loading the current rounds... the propellent is fragile and highly flammable.

    The amount of resources this technology would require to bring it to fruition would dwarf whatever tangible benefits it could bring.

    That is a lie.

    Liquid propellent is already widely used in a variety of engines and motors, they wont be inventing it all from square one, and the potential for achieving higher velocities would make it valuable. The massive reduction in flammable propellent in the vehicle would be an enormous step forward in safety.

    Having the ability to use precise amounts of propellent should allow more efficient and effective use of the gun.

    It was interesting for a time, when nobody was really certain what would it take to take down the next Soviet/Western supertanks, but 3 decades of sequestrations that forced investments in incremental improvements over every aspect of the gun system have shown that remarkable improvements are still possible even without resorting to exotica.

    Yeah, the west has struggled, but look at Russian progress in areas of ERA and APS... they led the way with smooth bore main guns, so now they might go further with new propellants.

    They could put a jacket around the barrel to pump the propellent around the barrel and back to the chamber so it acts as a barrel coolant too, or to just preheat the propellent to help it burn efficiently...
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    Post  lancelot Thu May 06, 2021 9:40 am

    Liquid propellants have a lot of issues. Stability and storage being some of them.
    I think for tanks electrical guns are a lot more viable. Or at least will be once electric storage improves.
    The future is the all electric tank.
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    Post  lyle6 Thu May 06, 2021 9:56 am

    GarryB wrote:
    New tank guns are not cheap to begin with.
    If you do it like the Germans and invent a new proprietary calibre, sure. Adapting a calibre for higher performance while maintaining most backward compatibility might not give you as large a performance increase but its certainly a whole lot cheaper and thus, deployable.

    GarryB wrote:
    Handling and storage for binary propellants would be much safer than with any solid propellent.

    Pumping fluids into a tank would be much faster and easier and safer than hand loading the current rounds... the propellent is fragile and highly flammable.
    And yet solid propellants are far safer and reliable to use. I'd rather the gun not blow up when I need it the most even if its a hassle in other ways.

    GarryB wrote:
    That is a lie.

    Liquid propellent is already widely used in a variety of engines and motors, they wont be inventing it all from square one, and the potential for achieving higher velocities would make it valuable. The massive reduction in flammable propellent in the vehicle would be an enormous step forward in safety.

    Having the ability to use precise amounts of propellent should allow more efficient and effective use of the gun.
    If it was easy it would've been done ages ago. There are overlaps for both applications but there are also divergence, and those differences are significant enough that it precludes one while the other is usable.

    GarryB wrote:
    Yeah, the west has struggled, but look at Russian progress in areas of ERA and APS... they led the way with smooth bore main guns, so now they might go further with new propellants.

    They could put a jacket around the barrel to pump the propellent around the barrel and back to the chamber so it acts as a barrel coolant too, or to just preheat the propellent to help it burn efficiently...
    The main appeal of high velocity smoothbore guns is that they are one of the cheaper yet the most effective way of reducing armored vehicles to scrap. More complicated and consequently expensive technologies that seek to supplant the tank gun miss the point entirely.

    lancelot wrote:Liquid propellants have a lot of issues. Stability and storage being some of them.
    I think for tanks electrical guns are a lot more viable. Or at least will be once electric storage improves.
    The future is the all electric tank.
    Storing the kind of energies required to propel a projectile with enough energy to punch through thick armor is inherently dangerous. Whether you do it by chemicals (propellants), mechanical (flywheel), or in electrical fields (ultracaps), its going to be dangerous once its released in an uncontrolled manner.
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    Post  GarryB Fri May 07, 2021 10:46 am

    Liquid propellants have a lot of issues. Stability and storage being some of them.
    I think for tanks electrical guns are a lot more viable. Or at least will be once electric storage improves.
    The future is the all electric tank.

    Current EM guns get impressive speeds but with tiny masses... and accuracy is a whole new area they have not even considered because they are still trying to get the required velocities with a useful projectile size.

    With a binary propellent stability should not be an issue at all in its separated state, EM acceleration looks useful but not all projectiles will react efficiently to magnetic acceleration forces.

    Liquid propellants are used in internal combustion engines where fuel is pumped in measured amounts into compartments and efficiently burned to drive pistons... in liquid fuelled rockets the different components are mixed which normally results in their instant and spontaneous combustion in the rocket nozzle...

    Getting the right chemical combinations to eliminate solid residue and to only create gas should not be that hard, the propellent might need to be microwaved to get it to detonate correctly... most of this is already used in Coalition.

    Ironically a tank full of lithium Ion batteries is probably more of a fire hazard than with a diesel engine... Russian diesel was well known for being hard to set off in the open air, but once lithium starts burning.... it will burn for days. And don't breathe in those fumes whatever you do.

    If you do it like the Germans and invent a new proprietary calibre, sure. Adapting a calibre for higher performance while maintaining most backward compatibility might not give you as large a performance increase but its certainly a whole lot cheaper and thus, deployable.

    I would think if anything, the calibre would be smaller with new types of high energy propellent...

    Certainly in terms of small arms ammo, a binary liquid propellent weapon would be much lighter in terms of ammo carried, but the brass case absorbs a bit of heat which is of course ejected from the gun as the empty case is ejected... but as I mentioned having the propellent pumped through the chamber and chamber end of the barrel will help cool the weapon down...

    And yet solid propellants are far safer and reliable to use

    Are they?

    Solid propellent stubs contain the fuel and the air needed to combust... a binary propellant liquid does not until it is mixed together in the chamber of the weapon.

    I'd rather the gun not blow up when I need it the most even if its a hassle in other ways.

    Guns blow up for all sorts of reasons... ironically one of the most dangerous things you can do in a large calibre shell is take out a lot of the solid propellent.

    Most large calibre guns have enormous propellent charges but when ignited they essentially burn from end to end pushing the projectile down and out the barrel.... if you take 1/3rd of the propellent out of them it leaves a cavity along which the flames from the propellent can run... meaning instead of the propellent burning from one end to the other, the entire length of propellent is exposed to flame at once... instead of a steady increase in pressure as it burns like a fuse from one end of the propellent block to the other, with it all burning at once the chamber will likely fail and destroy the gun.

    If the liquids fail to mix properly the only real risk would be the projectile not exiting the barrel... and lack of muzzle flash and no recoil will generally give you a strong hint about that...

    If it was easy it would've been done ages ago

    Useful chemical combinations need to be determined, but the idea is actually straight forward and widely in use in potato guns around the world... have you never build yourself one with old metal pipes and a can of CRC... A pipe with one end closed off but threaded... push your potato into the barrel making sure it fills the full width of the pipe...push it about a fist in then spray the CRC into the "chamber" and the screw the sealed end on and light the fuse that leads into the chamber and pop... Never use more than a quick squirt and make sure the barrel is not too long but is good and strong metal... I am pretty sure they did this a couple of times on Mythbusters...

    There are overlaps for both applications but there are also divergence, and those differences are significant enough that it precludes one while the other is usable.

    Actually Binary propellent makes internal combustion easier and more precise because you are not just venting in some air for the fuel to burn, you are pumping in precise amounts of fuel and oxidiser... the issue would be getting the cleanest burning combination and generating useful amounts of power.

    The main appeal of high velocity smoothbore guns is that they are one of the cheaper yet the most effective way of reducing armored vehicles to scrap. More complicated and consequently expensive technologies that seek to supplant the tank gun miss the point entirely.

    Look up higher in this thread in the video showing the new upgraded T-90... it is getting kill hits on target at 5km range whether stationary or moving... I think improvements in barrel aiming systems and optics etc etc has gone past worrying about making it expensive.

    The most critical thing is normally clean Sabot separation and they seem to have managed that.... I remember when it was confirmed that the T-62 had a 115mm smooth bore gun and western experts went ape shit because everyone knows they are not accurate... seems the accuracy problems of a smooth bore were overcome and its advantages have made it the gun of choice for most modern military forces around the world...

    Storing the kind of energies required to propel a projectile with enough energy to punch through thick armor is inherently dangerous. Whether you do it by chemicals (propellants), mechanical (flywheel), or in electrical fields (ultracaps), its going to be dangerous once its released in an uncontrolled manner.

    Agreed, and turret bustle and underfloor autoloaders and separate crew capsules are three methods of trying to minimise the threat to the crew.

    Just because it is called Binary does not mean it is two equal parts of something... there might be three fluids that on their own are not flammable, but when combined in a pressurised container and perhaps microwaved they will burn rapidly and completely... some fluid that might contain massive amounts of nitrogen or some other inert material in enormous volumes so when it "burns" it does not add enormous amounts of carbon into the air in any form.. it might just release lots of nitrogen... which is of course inert and already represents 70% of the atmosphere anyway.
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    Post  lyle6 Sat May 08, 2021 2:37 am

    GarryB wrote:
    I would think if anything, the calibre would be smaller with new types of high energy propellent...

    Certainly in terms of small arms ammo, a binary liquid propellent weapon would be much lighter in terms of ammo carried, but the brass case absorbs a bit of heat which is of course ejected from the gun as the empty case is ejected... but as I mentioned having the propellent pumped through the chamber and chamber end of the barrel will help cool the weapon down...
    When it comes down to it, its really all about reducing pressure. In the process of accelerating a heavy projectile to the required high velocities the gun and the projectile assembly would be subjected to immense loading stresses which might just cause a failure in the right conditions. To prevent this, you typically go for an increase in the calibre to spread out the forces on a much larger area and reduce the incurred material stresses while still more or less maintaining the same amount of force to accelerate the projectile.

    GarryB wrote:
    Are they?

    Solid propellent stubs contain the fuel and the air needed to combust... a binary propellant liquid does not until it is mixed together in the chamber of the weapon.
    Which implies there are many things that could happen between storage and firing that could go wrong in a binary propellant gun. The pumps for either of the feed lines might malfunction, releasing too much or too little of propellant or oxidizer. The mixer could work poorly and not mix in the required homogeneity. Also remember that you might have to adjust the mixture to match the ambient conditions as well. At least with a solid propellant the fuel and air mix is already took cared of in the factory - you don't have to bother with ensuring the right mixture is provided every firing cycle as in a bipropellant gun.

    GarryB wrote:
    Guns blow up for all sorts of reasons... ironically one of the most dangerous things you can do in a large calibre shell is take out a lot of the solid propellent.

    Most large calibre guns have enormous propellent charges but when ignited they essentially burn from end to end pushing the projectile down and out the barrel.... if you take 1/3rd of the propellent out of them it leaves a cavity along which the flames from the propellent can run... meaning instead of the propellent burning from one end to the other, the entire length of propellent is exposed to flame at once... instead of a steady increase in pressure as it burns like a fuse from one end of the propellent block to the other, with it all burning at once the chamber will likely fail and destroy the gun.

    If the liquids fail to mix properly the only real risk would be the projectile not exiting the barrel... and lack of muzzle flash and no recoil will generally give you a strong hint about that...
    That's the best case, and even then you lose the gun. The more likely scenario however is a catastrophic failure from an obstruction a little while later.

    GarryB wrote:
    Useful chemical combinations need to be determined, but the idea is actually straight forward and widely in use in potato guns around the world... have you never build yourself one with old metal pipes and a can of CRC... A pipe with one end closed off but threaded... push your potato into the barrel making sure it fills the full width of the pipe...push it about a fist in then spray the CRC into the "chamber" and the screw the sealed end on and light the fuse that leads into the chamber and pop... Never use more than a quick squirt and make sure the barrel is not too long but is good and strong metal... I am pretty sure they did this a couple of times on Mythbusters...
    I did that with PVC pipes for plumbing... while shouldering the thing like a bazooka.
    From what I know there are actually tons of viable fuel and oxidizer couples viable for use in liquid propellant guns so its not much of an issue.

    GarryB wrote:
    Actually Binary propellent makes internal combustion easier and more precise because you are not just venting in some air for the fuel to burn, you are pumping in precise amounts of fuel and oxidiser... the issue would be getting the cleanest burning combination and generating useful amounts of power.
    For which solid propellant users don't even need to bother. All the prep work has to done for you by the manufacturers working in sterile laboratory conditions which results in a product that is as safe and reliable as you can get. With a bipropellant you have to do the precise injecting and mixing on the fly, in less than optimum conditions. Think about how often the engine of your car does incomplete combustion - now imagine the frequency of such happening on your high velocity gun and what the failure might lead to. Doesn't inspire much confidence.

    GarryB wrote:
    Look up higher in this thread in the video showing the new upgraded T-90... it is getting kill hits on target at 5km range whether stationary or moving... I think improvements in barrel aiming systems and optics etc etc has gone past worrying about making it expensive.

    The most critical thing is normally clean Sabot separation and they seem to have managed that.... I remember when it was confirmed that the T-62 had a 115mm smooth bore gun and western experts went ape shit because everyone knows they are not accurate...  seems the accuracy problems of a smooth bore were overcome and its advantages have made it the gun of choice for most modern military forces around the world...
    Even if you sum up the support systems the tank gun still comes out ahead. Take the second closest to the tank gun in effectiveness, the ATGM fired from an attack helicopter, and that one comes attached with hundreds of thousands of dollars worth of optronics as well on top of a much more expensive platform.
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    Post  GarryB Sat May 08, 2021 10:07 am

    When it comes down to it, its really all about reducing pressure

    Not really... it is about getting to max allowable pressure as quickly as possible and maintaining that pressure till the projectile leaves the barrel.

    Max pressure means max acceleration down the entire length of the barrel.

    The problem with most propellants is that pressure builds up and reaches peak pressures as the projectile leaves the barrel.

    In one of the very old small arms threads they talked about optimising rifle calibre propellents specifically for barrel lengths to get the best possible performance in terms of acceleration... including low resistance plastic driving bands to reduce wear but also reduce friction in a rifled barrel while still getting the spin required for accuracy with spin stabilised rounds.

    In the process of accelerating a heavy projectile to the required high velocities the gun and the projectile assembly would be subjected to immense loading stresses which might just cause a failure in the right conditions.

    The mechanism and gun barrel and chamber should be rated for pressures 120% - 130% higher than the pressures normally used, so unless there is a fault or damage it should be fine to get to max pressure.... that being max safe pressure... not max possible pressure... as soon as possible and maintain that pressure and the round accelerates down the barrel.

    Most weapons have lots of propellant... a .22LR rimfire round has limited propellent space in the cartridge case so any barrel longer than about 43cm is not going to increase muzzle velocity at all, yet it is traditional for rifles to have 20-22 inch barrels... 50cm to 55cms long, which does nothing for added speed or accuracy... hunters just think a longer barrel means more power and better accuracy.

    To prevent this, you typically go for an increase in the calibre to spread out the forces on a much larger area and reduce the incurred material stresses while still more or less maintaining the same amount of force to accelerate the projectile.

    A larger calibre means more gas pressure can be pushed down the barrel.... I personally think the KPV 14.5mm heavy machine gun should be retired and replaced by the KPB with 23 x 115mm calibre ammo. The HE round has the same effective HE round as the Shilka round... same projectile but more propellent in the latter... but a sort of SLAP round for the 23 x 115mm round should be able to be made rather potent with its larger calibre allowing more energy with a small APFSDS projectile than the smaller calibre 14.5mm round.

    So you would get more HE and better AP for a round not much bigger.

    Which implies there are many things that could happen between storage and firing that could go wrong in a binary propellant gun.

    Of course they could but they could have ten different feed lines to the chamber... that would speed up "loading" and also add some redundancy... especially with pumps in the system able to move propellent from one tank to another if one feed line to the chamber fails.

    Aircraft have fuel pumps and fuel distribution systems in them and have had them for years.

    The pumps for either of the feed lines might malfunction, releasing too much or too little of propellant or oxidizer.

    You could have all sorts of safety systems including venting the chamber so you can start again if the mix is wrong.

    It means a turret bustle autoloader with sabot and penetrator dart but no propellent could be stored in there in rows and rows that would not be too badly effected by getting hit by enemy fire...

    The mixer could work poorly and not mix in the required homogeneity.

    Using 10 separate mixers all pumping into the chamber would allow faster loading and also reduce the effect if one or two are badly mixed...

    Bad batches of solid propellent do happen from time to time too...

    Also remember that you might have to adjust the mixture to match the ambient conditions as well.

    Which is a good thing you can't do with fixed loads of solid propellent.

    At least with a solid propellant the fuel and air mix is already took cared of in the factory - you don't have to bother with ensuring the right mixture is provided every firing cycle as in a bipropellant gun.

    Does it work efficiently in any temperature and in any condition...

    There will be issues with sealing the chamber without any sort of metal case, and the potential for contamination or clogging of lines.

    That's the best case, and even then you lose the gun. The more likely scenario however is a catastrophic failure from an obstruction a little while later.

    I think a failure of the round to exit the barrel would be noticed by the crew when the shell stub is extracted and ejected and the gas pressure that got the round that far down the barrel is all expelled into the turret...

    Interestingly with the Russian 125mm round, just loading another propellent stub with no fresh round might clear the blockage and allow them to continue.

    With a liquid propellent gun I would say another propellent load could be used to clear the blockage.

    Lots of dud rounds with my old 303... normal procedure is to keep the bolt closed and pointed down range and manually cock the bolt and fire again... it normally goes the second time but hold the gun away from your face when doing so... shooting glasses and hearing protection are a must.

    I did that with PVC pipes for plumbing... while shouldering the thing like a bazooka.

    Lots of fun till some moron tries to increase the power and ends up blinding himself or losing fingers or worse.

    For which solid propellant users don't even need to bother. All the prep work has to done for you by the manufacturers working in sterile laboratory conditions which results in a product that is as safe and reliable as you can get.

    The 125mm gun has two propellant options.... APFSDS with propellent around the long narrow projectile and its sabot, plus the standard propellent stub... so big propellent load for the APFSDS and standard propellent stub for everything else... except the missile.

    With a liquid powered gun you could have the propellent load automated based on the numbers from the ballistics computer and fire control system... a bit more energy for long range shots and a bit less for soft targets at close range.

    Think about how often the engine of your car does incomplete combustion - now imagine the frequency of such happening on your high velocity gun and what the failure might lead to. Doesn't inspire much confidence.

    Fuel injection in car engines is amazing... from 2,000 rpm to 7,000 rpm it does it faultlessly for hours on long trips... it is amazing when you consider one r is all four cylinders firing... so 8,000 to 28,000 controlled explosions per minute and it can keep that up for many hours at a time...

    Even if you sum up the support systems the tank gun still comes out ahead. Take the second closest to the tank gun in effectiveness, the ATGM fired from an attack helicopter, and that one comes attached with hundreds of thousands of dollars worth of optronics as well on top of a much more expensive platform.

    In a lot of combat to date, tank on tank warfare is not common... land mines and RPGs and IEDs are probably the biggest killers of tanks these days...

    Don't get me wrong, a tank is an amazing beast, but improvements in communications between forces means that pretty soon if you need something destroyed with a big gun it could be called in from several kms away and directed by drone.

    I mean new anti tank vehicles with vertical launched guided 15km range anti tank missiles with top attack capability, armour is really going to have to step up...

    Russia has an excellent and improving air defence capacity but HATO would be in real trouble...

    I rather suspect the future of ammo propellent advancement will be a mix of liquids and electric to create plasma based propellent for enormous velocities.

    EM might boost that further.

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