Main Battle Tanks and Armour Technology

[Sovngard]

I think some things here are exaggarated. Obviously I agree that OFL120F2 could have similiar performance to M829A1 but at 4500m? Nah, better ammunition like DM53 have roughly comparable performance when fired from Rh-120 L55 gun to M829A3 fired from M256 L44. I would rather say it is definetely exaggarated.

I share the same opinion.



Somebody has the penetration values of the OFL120F1 at 2000 meters ? Apparently, there is a formula for calculate this, no ?

 

[Dazzler]

I share the same opinion.



Somebody has the penetration values of the OFL120F1 at 2000 meters ? Apparently, there is a formula for calculate this, no ?

Should i call @militarysta, @methos, @Dejawolf to do the calculations please?

 

[Dejawolf]

Should i call @militarysta, @methos, @Dejawolf to do the calculations please?

what would be needed is muzzle velocity, penetrator length and diameter for a decent estimate.

 

[methos]

Based on the available data for the 120 mm DM 43A1 APFSDS, the French OFL F1 should penetrate:

574 mm into 270 HB steel at 2,000 m and 0° impact angle.
603 mm into 230 HB steel at 2,000 m and 0° impact angle.
671 mm into 270 HB steel at 2,000 m and 60° impact angle.
705 mm into 230 HB steel at 2,000 m and 60° impact angle.

For comparision with the M829A1 APFSDS: an estimate from a TankNet member (Lieste) put it 684 mm at 60° at 2,000 m of 230 HB steel. M829A1 also has a much greater deceleration than OFL F1/DM 43A1.
Honestly I don't know why some estimates are made with 230 HB steel, when even the cast turret of the was made T-72 of 260-270 HB steel.

 

[Dazzler]

just a random M1A1 i found...

 

[Dazzler]

the M1 with 105 mm L7 gun...

 

[Damian]

just a random M1A1 i found...

This photo is not that random, actually what you see are old M1's and M1A1's that were not modernized and are in a long storage at Sierra Army Depot. There are approx 2000 M1/M1A1 tanks stored there as a low readiness reserve. Some of them will be eventually modernized to newer standards, some will be converted to specialized vehicles like ABV or HAB and some will be offered for export, of a client will be found, these vehicles will be modernized and modified for export standards.

Most of these are also in actually rather good technical condition, this is because of climate in a region where Sierra Army Depot is placed.

Also approx 1000 more M1 of different variants are stored at Anniston Army Depot.

For people that are interested to see how many tanks are stored at these depots, you can see them in relatively high quality photos from above at Google Maps.

the M1 with 105 mm L7 gun...

Actually not, this seems to be some test M1, maybe from low rate initial production, as we can see the gun have a muzzle device not seen on series vehicles. And the gun is not pure L7. It is a upgraded M68A1, which can fire more powerfull ammunition than M68 which is american variant of the L7.

 

[Dazzler]

 

[Dazzler]

Actually not, this seems to be some test M1, maybe from low rate initial production, as we can see the gun have a muzzle device not seen on series vehicles. And the gun is not pure L7. It is a upgraded M68A1, which can fire more powerfull ammunition than M68 which is american variant of the L7.

Thanks, i forgot the American designation for their version of British L7 i.e. The M68.

 

[Dazzler]

@Damian

i dont know the credibility of this author but he also mentions Abrams trials in Pakistan, whats important is that he lists his personal account of HIT and AK project.


War, Coups and Terror: Pakistan's Army in Years of Turmoil - Brian Cloughley - Google Books

 

[Damian]

Seems more credible, but he does not describe details, and he is wrong that M1 performed poorly in desert conditions. As I said, before induction in to service, American tanks (and NATO tanks overall) needs to pass extensive trails in arctic and desert conditions.

What is more important, USA is a large country which means they also have their own deserts. Units equipped with M1's also stationing in states that have mostly desert conditions, and as far as I am aware, no significant problems with reliability were confronted.

What is more important, is that on your video, we see M1A1 variant, in which all major problems were long time ago solved, and this variant participated in 1990/1991 Gulf War. If M1A1 was tested in Pakistan in 1988, then it didn't received any major upgrades in it's automotive components up to XXI century where engines were modernized within TIGER program.

So again, it seems that claim about poor reliability in desert conditions is a bogus story.

I think it is more about attempting to justify why the deal was never finalized and Chinese tank was choosen, which have obvious deficiencies compared to M1 or other NATO tanks.

Very silly is also this argument that M1 was far more complicated, when in fact from mechanical point of view, M1 is a simpler tank than Al Khalid even. Gas Turbine engine have lesser moving parts than a Diesel, which means it is simpler, while lack of autoloader also means that vehicle design is simpler and have less moving parts.

Other thing is of course production costs and service life costs. M1 is definetely more expensive, and for example the most wearing components of it's gas turbine engine are more expensive than in case of a diesel powered tank.

My theory is that deal was not finalized due to several reasons:

A) US - Pakistan disagreements on nuclear weapons.
B) Increasing cooperation between Pakistan and China, which meant that classified technology from M1A1 could leak to PRC.
C) Production and service life costs of M1 were beyond Pakistans capabilities.

I think these reasons are very close to reality. And a story about poor performance during tests are mostly attempts to justify the situation and are in some cases obviously results of observations made by people that do not have a knowledge about AFV's.

 

[militarysta]

From their perspective, the OFL 120 F1 (fired from the CN120-26 52-calibers gun) has the penetrating capability of the German DM43 (same dart) but at 3000 meters instead of 2000, thanks to the CN120-26's barrel lenght.
And the OFL 120 F2 would be similar to the M829A1 in term of penetrating capability but listed to 4500 meters instead 2000...



What do you think about this ?

Based on the available data for the 120 mm DM 43A1 APFSDS, the French OFL F1 should penetrate:

574 mm into 270 HB steel at 2,000 m and 0° impact angle.
603 mm into 230 HB steel at 2,000 m and 0° impact angle.
671 mm into 270 HB steel at 2,000 m and 60° impact angle.
705 mm into 230 HB steel at 2,000 m and 60° impact angle.

For comparision with the M829A1 APFSDS: an estimate from a TankNet member (Lieste) put it 684 mm at 60° at 2,000 m of 230 HB steel. M829A1 also has a much greater deceleration than OFL F1/DM 43A1.
Honestly I don't know why some estimates are made with 230 HB steel, when even the cast turret of the was made T-72 of 260-270 HB steel.

I Agree whit Methos, what more - polish sources give DM43 from L-44 circa 560mm RHA at 2000m at 90. plate -what is consist whit Methos, it's important to notice that WITU norms are more severe (ristrict) then standard NATO ones becouse some penetration level in estimatous not as in NATO rule (50% rounds +1) but as in old WarPac - more then 70% must overcome some penetration level. So only for this there is circa 6-8% difrence so if polish norm give 560mm for DM-43A1 circa 560mm than NATO shoud give circa 600mm.


The same for DM-33A1 data is given for French OFL F1, but for DU OFL F2 other then WITU sources give ~640mm RHA at 2000m at 90.plate what shoud be consist whit 8-10% bigger RHA penetration for standard DU rods then standard WHA ones:

8-10% from 640mm is 51-64mm bigger for DU reson, so if we substract this value we shoud have "normal" non DU OFL F1 value:
640-51 to 64mm = ~590-570mm what is pretty the sam as for DM-33A1 - upper value is consist whit "NATO norm" lower value is close to the WarPac and WITU norm.
And both are consist whit Methos estimatous
So confirmed?

He told me that the Emiratis have trialed their Tropicalized Leclerc by shooting 120mm sabot round on it (frontal part). (...)
Another good friend who is an AMX-10RC gunner told me the same story (this rumor circulated for a while in the Armoured Cavalry Branch) but in addition he mentionned that the round used was the OFL 120 F2 (an OFL 120 F1 with a DU penetrator (with slightly slower velocity than the F1)).

It's really posible and give us frontal protection levle for Leclerc export version bigger then 600mm RHA for front. What is really posible and obvious for modern western tank. And in some way explain why IMI (Israel) very fast changed from 105 to 120mm gun (M1 in Egipt) and then change M332 to mucht better M338 APFSDS - first is circa 600-650mm RHA, second slighty better whit abilities to overcome modern ERA and NERA plates.

Unfortunately, no information about the target range...

Ussaly it's no bigger then 2000m and no lower then 1300m.

although the poor monkeys placed inside were stunned and bleeding from their ears...

It's really posible - propably those mankey where "fixed" on crew seats but without helmets. More or less armour must stop ~6-8MJ hitting the armour on short distanse. So noise can be huge.

 

[Sovngard]

Ussaly it's no bigger then 2000m and no lower then 1300m.

Probably, but the Leclerc's commander has emphasized to the fact that there is a vast training range in the UEA, allowing to shoot at more than 4000 meters.

It seems to me that the Greeks had shot dozens of russian 125mm APFSDS on their Leopard 2A6 HEL at only 1500 meters.
With the exception of the wedge-shaped, spaced add-on armour fitted since the A5 model, the armor package had been changed since the A4 ?

 

[methos]

The weight of the Leopard 2A5 turret increased drastically, this implies that the armour package was changed.

 

[militarysta]

Probably, but the Leclerc's commander has emphasized to the fact that there is a vast training range in the UEA, allowing to shoot at more than 4000 meters.

very advanced FCS and very good stabilisation and gun in Leclerc allowed for sucht action. It's mix of the FCS and ammo.
Now DM-11 allowed to shoot up to 5000m for example.

It seems to me that the Greeks had shot dozens of russian 125mm APFSDS on their Leopard 2A6 HEL at only 1500 meters.

During greek Leo-2A6 turrets tests they used M332 APFSDS from Israel. It was very modern in 1990s round -whit long WHA rod, and really good penetration 600-650mm RHA at 2000m. In some vay it was analoge never introduced in to service 3BM42M Lekalyo (the same penetration). Leopard -2A6 turret windstand 18/20 shots (ussaly is given this value). What is important - NERA panels where not attached to the turret so real protection will be slighty bigger propably.

With the exception of the wedge-shaped, spaced add-on armour fitted

It's NERA or NxRA armour. Maybe even SLERA.

since the A5 model, the armor package had been changed since the A4 ?

Yes -whole turret is ~4000kg heavier, while without NERA pannels pure armour insert will be heavier at 2250kg at least. Not even mentioned about new technology and in fact armour generation.

 

[Dejawolf]

very advanced FCS and very good stabilisation and gun in Leclerc allowed for sucht action. It's mix of the FCS and ammo.
Now DM-11 allowed to shoot up to 5000m for example.


During greek Leo-2A6 turrets tests they used M332 APFSDS from Israel. It was very modern in 1990s round -whit long WHA rod, and really good penetration 600-650mm RHA at 2000m. In some vay it was analoge never introduced in to service 3BM42M Lekalyo (the same penetration). Leopard -2A6 turret windstand 18/20 shots (ussaly is given this value). What is important - NERA panels where not attached to the turret so real protection will be slighty bigger propably.



It's NERA or NxRA armour. Maybe even SLERA.


Yes -whole turret is ~4000kg heavier, while without NERA pannels pure armour insert will be heavier at 2250kg at least. Not even mentioned about new technology and in fact armour generation.

if you go by the german 2A5 mannerheim configuration, it is a total of 3850kg heavier than the A4. there is no additional front hull armour on the german A5, however there was some changes made for the sideskirts. the older perforated steel+rubber skirts were swapped with hardened steel skirts, and above the original
thick sideskirts was added some additional armour panels about 60mm thick.
going by a volume of 0.022m^3 the armour panels should weight about 150kg each.
side skirt volume: old leopard 2A4 skirts were fairly thin around 15mm, with a volume of 0.0317m^3 and assuming 50/50 rubber/steel, they weight about
82kg each.
on the mannerheim leopard, the skirts have been made thicker, about ~25mm but a bit smaller which gives a volume of 0.0477m^3
and a weight of about 375kg each.
turret was also slightly extended with some additional stowage space. the metal there is fairly thick, approx 15mm, with a volume of about 0.031m^3 i've estimated about 250kg extra.
now adding all of this together, and subtracting from 3850kg:
150*2 = 300, 375-82 = 293, 293*2 = 586,
300+586+250 = 1136kg
3850-1136 = 2714kg

hrm, and i forgot the addittional armour on the turret glacis. there's some blocks added on the loaders front roof there to maintain uniform front turret protection.
the wedges on the leopard, if made entirely out of 20mm steel would weight about 1.2 tons.
the wedges are definitely about 20-25mm thick, but behind the wedges, elements about 30-40mm thick are mounted. this could be NERA,
but i think it's more likely hardened steel designed to break and deflect rounds before impacting the main turret armour.

 

[methos]

thick sideskirts was added some additional armour panels about 60mm thick.

This already happened on the Leopared 2A4 from batch 6 (beginning with the 97th vehicle of that batch). The only change which was made on the Leopard 2A5 was the exchange of perforated steel rubber side skirts with high hardness steel skirts.

on the mannerheim leopard, the skirts have been made thicker

It is Mannheimer configuration (from Mannheim, a city in Germany in which the Leopard 2 user states met) and not "mannerheim" (which is a Swedish/Finish noble family).

turret was also slightly extended with some additional stowage space.

The additional storage space consists only contains the camouflage nets, tarpaulin, a cable role and the stop-blocks.

there's some blocks added on the loaders front roof there to maintain uniform front turret protection..

Are you sure that there were armour plates/blocks of armour added? None of the Leopard 2 books I have read mention it, even the booklets specialized on the Leopard 2A5.

the wedges on the leopard, if made entirely out of 20mm steel would weight about 1.2 tons.
the wedges are definitely about 20-25mm thick, but behind the wedges, elements about 30-40mm thick are mounted. this could be NERA,
but i think it's more likely hardened steel designed to break and deflect rounds before impacting the main turret armour.

It does very likely look like this German armour array tested in 1993. The wedge armour is clearly made of multiple plates (in my opinion 4) and an interlayer material can be seen at different places.

 

[militarysta]

hrm, and i forgot the addittional armour on the turret glacis. there's some blocks added on the loaders front roof there to maintain uniform front turret protection.
the wedges on the leopard, if made entirely out of 20mm steel would weight about 1.2 tons.
the wedges are definitely about 20-25mm thick, but behind the wedges, elements about 30-40mm thick are mounted. this could be NERA,
but i think it's more likely hardened steel designed to break and deflect rounds before impacting the main turret armour.

Single NERA wedge weight 500kg. It's even visible on the photo.

 

[militarysta]

It does very likely look like this German armour array tested in 1993. The wedge armour is clearly made of multiple plates (in my opinion 4) and an interlayer material can be seen at different places.

Layers are visible here:

Eacht wall of the NERA wedge have steel - interlayer material - steel - air gap - steel -- interlayer material - steel build.
So eacht wall have double NERA layers.

 

[Sovngard]

The wedges on the leopard 2A5S (STRV-122) and on the A7+ urban warfare kit look different, maybe fitted with some kind of composite inserts