Main Battle Tanks and Armour Technology

[Damian]

I know about those problems, but if it is true that in Leopard 2A6 new stabilisator was not adopted for longer gun (using older one for 2A5) then reported accuracy issues are real.

Problems were during initial test phase, stabilization was upgraded after tests and initial problems, as I said, it was all solved. Americans also solved their problems with stabilization, but in the end they didn't adopted new gun. They even tested much longer XM291 on standard M1A2.

I don't know if this M1A2 is armed with XM291 120mm version or 140mm version, as XM291 was bicalliber weapon, both options are possible.

Older M1 variant tested with older version of XM291.

Swiss rounds were unitary or two-piece ?

Unitary, two piece is immposible to be stored there, unless You want significant reduction of quantity in stored ammunition.

 

[hest]

Leopard 2A5 got already a new gun stabilization designed for the L/55, the Leopard 2A5 tank was made so that only the gun had to be changed for upgrading to Leopard 2A6; recoil mechanism, FCS, stabilization etc. all was improved/changed and is the same on both Leopard 2A5s and Leopard 2A6s.

E-WNA stabilisator was developed for L/44 gun of early Leopard 2A5 if I am correct, and was not changed, so I do not know on what degree was it suitable for longer gun. Relative error increase in adoption of new gun is probable, aren't there any figures ?

 

[Damian]

E-WNA stabilisator was developed for L/44 gun of early Leopard 2A5 if I am correct, and was not changed, so I do not know on what degree was it suitable for longer gun. Relative error increase in adoption of new gun is probable, aren't there any figures ?

You need to ask Methos or Militarysta, my main interest are American tanks.

However I know that Americans found a way to solve problems with stabilization different than changing or upgrading stabilization system.

 

[Akim]

Unitary 140-mm projectile weighs more than 45 kg. Not very pleasant to wear such a pleasure!

 

[Akim]

140-mm gun
http://defenceforumindia.com/forum/land-forces/39363-tank-guns-ammunition-15.html

 

[hest]

This question arised as I was thinking about perspectives of increasing firepower on current tanks.

It is aknowledged that further improvement will come from higher pressure which implies bigger chamber dimensions, and it is not serious to handle heavy amunition manually.

It is also true that upgrades will be performed on existing tanks, and deep modifications are not expected.

So as realised, most tanks would not receive vast improvement (Leopard, Abrams) in that aspect as new chamber and adoption of automatic loading mechanism requires significant turret redesign. But Leclerc design is the most suitable.

 

[Damian]

US have developed autoloader that can be fitted in existing turrets.

FASTDRAW.

Meggitt company compact autoloader.

Both autoloaders are high capacity designs, FASTDRAW can store 36 rounds in bustle, while compact autoloader stored 34 rounds, for both + 8 rounds in standard hull ammo magazine.

 

[hest]

For example very notable increase in firepower can be added to all current tanks, from T-72 to latest T-90.

It does not require any redesign, just adoption of new gun 2A82 with extended chamber dimensions and modified autoloader to host new projectiles.

I showed earlier, gun 2A82 with bigger chamber

And modified autoloader (red) as compared to current

It seems that it can host as well as bigger propelling base, even longer APFSDS. With notable increase in pressure and power it should approach 140 mm ammunition, piercing throught any current frontal tank armour (in perspective, up to 900 mm of RHA perforation).

 

[Akim]

@Damian So, the fourth member of the crew disappear?

 

[hest]

US have developed autoloader that can be fitted in existing turrets.

FASTDRAW.

Meggitt company compact autoloader.

Both autoloaders are high capacity designs, FASTDRAW can store 36 rounds in bustle, while compact autoloader stored 34 rounds, for both + 8 rounds in standard hull ammo magazine.

But question is not only adoption of autoloader, but bigger chamber dimensions, bigger ammunition and ability to handle it, would require significant redesign.

This is autoloader designed for existing ammunition, which is not the point.

 

[Damian]

@Damian So, the fourth member of the crew disappear?

Not nececary, former loader can for example control RWS or be more concentrated on radio and BMS system so commander can better focus on commanding. There are both concepts or lack of 4th crew member, or finding him new tasks.

But question is not only adoption of autoloader, but bigger chamber dimensions, bigger ammunition and ability to handle it, would require significant redesign.

Look at some posts earlier, there is photo of M1A2 with XM291, most probably in 140mm version on firing range (gun shape is similiar to the 140mm version installed in "Thumper" test variant.

This is autoloader designed for existing ammunition, which is not the point.

Design can be allways adapted to the bigger calliber, there is not technical problem with this, only money are needed to pay for slight redesign.

 

[hest]

In current tanks extension of chamber needed to host significantly longer unitary rounds requires significant redesign of turret, not simple adoption of new gun.

Significant redesign and adoption of autoloader will likely take all ideas back, as now nobody (except Russia, but it is different story) will get radical upgrades and vast expense, but will focus instead on conservative modernisation of existing fleet.

 

[Damian]

In current tanks extension of chamber needed to host significantly longer unitary rounds requires significant redesign of turret, not simple adoption of new gun.

If longer rounds need to be stored, bustle can be extended, not a big problem due to nature of design. New turret can also be designed, there is no problem for this, and is cheaper than designing completely new vehicle.

Significant redesign and adoption of autoloader will likely take all ideas back, as now nobody (except Russia, but it is different story) will get radical upgrades and vast expense, but will focus instead on conservative modernisation of existing fleet.

Actually Russia will be first to induct completely new design, others are just practial, especially US, they just wait for what will appear, and then they will correctly answer the new threat, this is smart move.

Also You do not know how exactly upgraded will be NATO vehicles.

For example M1 series. ECP1 means Engineering Change Proposal 1 it is only proposal phase, where different projects can be presented to the US Army for acceptance.

 

[hest]

If longer rounds need to be stored, bustle can be extended, not a big problem due to nature of design.

If you look at all examples with 140 mm, they passed throught significant modifications, redesign, relating to munition of increased lenght and extended gun elements, chamber.

It is not as simple as adoption of new gun in Soviet style autoloader, T-72, T-90, where no significant changes are made, but will require apart from gun, redesign, rearrengement of internal elements, adoption of autoloader, modifications in storage to handle longer rounds, elimination of crew member which in all is rather deep and costly upgrade,

Actually Russia will be first to induct completely new design, others are just practial, especially US, they just wait for what will appear, and then they will correctly answer the new threat, this is smart move.

Of course it wouldn't be inmediate, this requires significant early investment.

 

[Damian]

If you look at all examples with 140 mm, they passed throught significant modifications, redesign, relating to munition of increased lenght and extended gun elements, chamber.

It is not as simple as adoption of new gun in Soviet style autoloader, T-72, T-90, where no significant changes are made, but will require apart from gun, redesign, rearrengement of internal elements, adoption of autoloader, modifications in storage to handle longer rounds, elimination of crew member which in all is rather deep and costly upgrade,

If there will be nececity new turret will be designed, now problem with this.

Of course it wouldn't be inmediate, this requires significant early investment.

Yes, but for example under GCV program, there are allready besides IFV sub programs, considered secondary vehicles sub programs.

 

[hest]

If there will be nececity new turret will be designed, now problem with this.

Problem is not ability. Current leadership wants only conservative upgrades, so relatively costly redesign will likely not pass.

Yes, but for example under GCV program, there are allready besides IFV sub programs, considered secondary vehicles sub programs.

In perspective yes, but all current efforts are focused on existing modernisation at the moment (Abrams upgrade phases, etc).

 

[Damian]

Problem is not ability. Current leadership wants only conservative upgrades, so relatively costly redesign will likely not pass.

And how do You know what leadership wants? You do not know. During my whole learning process about AFV's, I also talked with engineers, and they said that what is in press, and what will be the final product, are two very different things.

In perspective yes, but all current efforts are focused on existing modernisation at the moment (Abrams upgrade phases, etc).

Because there is no nececity for new vehicle, for current threats, existing but upgraded design are more than sufficent, when new threats will emerge, new design will be inducted.

 

[militarysta]

About Leopard 2A6 and on

There was some criticism regarding performance of these new versions, about added weight of frontal armour wich reduced tank balance (thus some users partially renounced uparmouring hull ?) , and adoption of new L/55 gun with accuracy problems

1. Those "criticism" was on btvt and wladimir page.
2. There where no "accuracy problems". In fact L-55 is more accurate then L-44 on mid and large distance.
3. Whole BS story about L-55 (copied on many russian pages) had begun in real problem with DM53 propelant charge. It was sensitive to temperature and many times FCS had problems whit proper values when propelant charge was to sensetive. And that was the reson problems whit accuracy but only in some whater conditions. In DM52A1/DM63 those problem was solved.

It is known that additional lenght of gun contributes negatively to it's control, being more susceptible to movement, etc, but stabilisator used in Leopard 2A6, E-WNA was first adopted in Leopard 2A5 version for older L/44 gun (it was not changed ?) so indeed there could be problem with accuracy as no measures were taken.

No, it's not true -stabilisation EWNA was developed for L-55 gun and it was part 140mm gun developmend program. In fact Leopard-2A5 had all components redy for L-55.

I know about those problems, but if it is true that in Leopard 2A6 new stabilisator was not adopted for longer gun (using older one for 2A5) then reported accuracy issues are real.

EWNA was developed for L-55 not L-44. Strv.122 and A5 use L-44 for only cost reson, and developmend calendar. In fact EWNA was part bigger program to placed 140mm in Leo-2 turret. As I said - the whole "problems" are myth and true problem was ammo not gun or stabilisation.

It seems that it can host as well as bigger propelling base, even longer APFSDS.[/qoute]
It's imossible in non changed hull -due to carossel autoloader limits:


maybe in Armata hull whit complete diffrent ammo store system (vertical carosselle) it is possible. But definetly not in typical T-72/90 hull.

 

[hest]

1. Those "criticism" was on btvt and wladimir page.
2. There where no "accuracy problems". In fact L-55 is more accurate then L-44 on mid and large distance.
3. Whole BS story about L-55 (copied on many russian pages) had begun in real problem with DM53 propelant charge. It was sensitive to temperature and many times FCS had problems whit proper values when propelant charge was to sensetive. And that was the reson problems whit accuracy but only in some whater conditions. In DM52A1/DM63 those problem was solved.

2 Any figures, stabilisation error ?

No, it's not true -stabilisation EWNA was developed for L-55 gun and it was part 140mm gun developmend program. In fact Leopard-2A5 had all components redy for L-55.

EWNA was developed for L-55 not L-44. Strv.122 and A5 use L-44 for only cost reson, and developmend calendar. In fact EWNA was part bigger program to placed 140mm in Leo-2 turret. As I said - the whole "problems" are myth and true problem was ammo not gun or stabilisation.

These claims are not confirmed.

Gun of increased lenght is harder to stabilise due to increased oscillation effects. It may be that EWNA stabilisator can be modified to handle new gun, but it would not be certain if its solution, or it would still be relatively less accurate (error as compared to older gun).

What is true is that this system was first adopted for L/44 gun, and if it was not modified it shouldn't be expected to be as effective for longer gun.

It seems that it can host as well as bigger propelling base, even longer APFSDS.[/qoute]
It's imossible in non changed hull -due to carossel autoloader limits:


maybe in Armata hull whit complete diffrent ammo store system (vertical carosselle) it is possible. But definetly not in typical T-72/90 hull.

But you are using as reference older autoloader

Current modernised in T-90A holds APFSDS (active part) more than 50 mm longer than original (~690 mm to >740 mm)

For 2A82 it has different conturn as showed, I do not confirm, but longer projectile is a possibility.

 

[militarysta]

2 Any figures, stabilisation error ?

Not to shown in public. I can post only L-44 figures.
In fact L-55 is about 15% more accurate then L-44.

These claims are not confirmed.

Yes, in 90% Leo-2 monography EWNA is desribe ad system for L-55 so it's "not confirmrmed"?
LOL It's not my problem that rusian sources haven't bigger idea abour Leopard-2 and are full of nonsense like smaller LOS (btvt) or "monlith steel armour in gun mantled mask (vladimir). Change sources men.

It may be that EWNA stabilisator can be modified to handle new gun, but it would not be certain if its solution, or it would still be relatively less accurate (error as compared to older gun).

EWNA was modified to hanle L-44 gun becouse it was developed to handle L-55 gun. Do you undrstand what I and methos wrote?

What is true is that this system was first adopted for L/44 gun, and if it was not modified it shouldn't be expected to be as effective for longer gun.

Lidky, are You stupid, or you forgot how to read in english?
I post very clearly:
EWNA and whole stabilisatin where developed for L-55 gun during KWS program. And new stabilisation system, computer, etc where developed especilly for L-55 longer and havier gun. And there is no problem whit L-55 accuracy. It's myth.

And if you so trust russian language sources check how they describe LOS in Leopard-2A4.(in most of them 65/45cm). Do you want photos? Then you will see how realible can be estern sources in Leopard-2 thema...

But you are using as reference older autoloader

I based not on autoloader but on T-72 Hull widh. You can't overpass that detail - T-72 hull have to small widh to handle longer APFSDS projectile in carosselee style autoloader. In Ob.188A2 it's limit - 740/750mm long.

For 2A82 it has different conturn as showed, I do not confirm, but longer projectile is a possibility.

And it's exatly the same as red line on my draw. And need change hull in new tanks. And As I posted - in Ob.1888A2 is max lenght. There is no possibility to put longer penetrator in horizont carrossele autoloader.