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On 3/17/2020 at 8:17 AM, Wiedzmin said:

@Militarysta on 60 deg there a two layers of Erawa2 or some sort of dumper ? and is there any detailed info and pics of results after detonation ?

 

Well from my article in FO! :https://fragout.uberflip.com/i/1150145-frag-out-magazine-25/79?

There is description. Generally - prototypes of Pzf-3T and IT600 has faild vs ERAWA in 2000  (losing 50% penetrating power) but finall PzF-3IT600 whit new main "super fast" SC perforated in 2007 ERAWA-2 without any problem (lost only ca 100-150mm RHA).

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On 3/18/2020 at 9:38 AM, Wiedzmin said:

any specific numbers ?

 

No details, usally "super fast SC" is more then 10,5km/s

 

22 hours ago, Wiedzmin said:

@Militarysta

btw interesting, only steel part of ERAWA is throwable plate ?

 

No, this ERAWA-2 from your post is lightweigt version based on aluminium alloy casette and HHS throwable plates. Normal ERAWA-2 is based on HHS casette.

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Wiedzmin, in case of ERAWA-1 both upper and lower metal parts of case are flyer plates. Mounting beams are not sturdy enough to stop lower part (base) of case movement and are being smashed in the process. So, even if only upper part looks like flyer plate, both are flyer plates. And in ERAWA-2 there is one more plate between H.E. layers.

 

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On 3/18/2020 at 8:42 AM, Militarysta said:

 

Well from my article in FO! :https://fragout.uberflip.com/i/1150145-frag-out-magazine-25/79?

There is description. Generally - prototypes of Pzf-3T and IT600 has faild vs ERAWA in 2000  (losing 50% penetrating power) but finall PzF-3IT600 whit new main "super fast" SC perforated in 2007 ERAWA-2 without any problem (lost only ca 100-150mm RHA).

The main difference between 3-T and and final 3-IT600 that might explain such results, is precursor warhead shape.

main-qimg-e10278338701f449c103dce5b1e52c slide9-n.jpg

 

During other tests EFP precursor with 40 mm diameter proved almost totally ineffective against ERAWA-2 (no perforation of upper plate).

109.jpg

 

I think that it's impossible to fully reduce reactive armour efficiency by simply increasing jet tip velocity (with copper liners it's also difficult to exceed 10 km/s) taking into consideration this fragment of "Evolution of ERA for light-armoured fighting vehicles" :

Quote

The plastic explosives used in the first generations of ERA featured high sluggishness. Detonation of the explosive compound took place only 3…5μs after the impact of the shaped-charge jet. As a result the jet leader managed to get through the ERA (Fig.6). With the velocity of 9…10km/s and weight of 5…10 gram, the slipped leader could pierce 50…80 mm of steel armor that is sufficient to disable LAV.

It is possible to reduce or completely prevent the breakthrough of the jet leader by using high-sensitive explosives, but in this case the problems of ERA element inflammation when perforated by small arms bullets and ERA element detonation under the impact of 30mm and heavier ammunition become more urgent. These problems have been solved in ERA with 4S24 elements (Fig.7).

 

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Well, jet tip is faster in HEAT warhead than in EFP one. :D But that's not the point. 

 

The idea of EFP precursor in tandem warhead is quite simple - initiate the ERA but do not take large part in classic penetration. In this case to initiate ERAWA you need to have effective HEAT warhead. As you can see in one article you posted there were one type of warheads which caused the ERA explosion. They have also 42mm caliber but they penetrate ~260mm of steel alone. 

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That 3-T precursor liner is circa 140-145 degree cone. SCs with so wide angle cones lay in transition area between EFPs and classic jets.

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On 3/21/2020 at 12:22 AM, Zadlo said:

Well, jet tip is faster in HEAT warhead than in EFP one. :D But that's not the point. 

 

The idea of EFP precursor in tandem warhead is quite simple - initiate the ERA but do not take large part in classic penetration. In this case to initiate ERAWA you need to have effective HEAT warhead. As you can see in one article you posted there were one type of warheads which caused the ERA explosion. They have also 42mm caliber but they penetrate ~260mm of steel alone. 

The purpose of using EFP precursor in this case is NOT to initiate ERA, 4S20 and 4S22 won't detonate on EFP (and other low velocity projectiles) impact. Tandem RPGs  like Panzerfaust 3-T, PG-7VR (russian ATGMs don't)  use non-initiating precursors to increase the safety of infantryman using them against tanks with ERA at short ranges. On the other hand, such precursors are almost useless against targets with good passive protection against HEAT.  On the picture below it is shown what they do with Kontakt-5.

2499672_800.jpg

 

On 3/20/2020 at 12:29 PM, TWMSR said:

Wiedzmin, in case of ERAWA-1 both upper and lower metal parts of case are flyer plates. Mounting beams are not sturdy enough to stop lower part (base) of case movement and are being smashed in the process. So, even if only upper part looks like flyer plate, both are flyer plates. And in ERAWA-2 there is one more plate between H.E. layers.

 

This lower part is quite heavy and will move with lower velocity than upper plates. Moreover these mounting beams will additionally slow it down. That's why such movement shouldn't be efficient against cumulative jet.

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5 minutes ago, J.J.S. said:

PG-7VR (russian ATGMs don't)  use non-initiating precursors to increase the safety of infantryman using them against tanks with ERA at short ranges.

what ?

 

PG-7VR.jpg

 

 

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The shape of liner is not all.  To reduce energy of of jet/slug it is possible to either decrease its velocity or density.  I think that you forgot what Vasiliy Fofanov wrote about PG-7VR:

Quote

Тандемность РПГ-29 строится на принципе несрабатывания ДЗ под воздействием лидера. То есть лидер расчищает ДЗ без срабатывания, потом основной заряд бьет в пустое место. Соот ветственно если подправить ДЗ чтобы она таки срабатывала, результат будет даже хуже чем если бы лидера вообще не было.

 

Fragment of article from russian miliary journal Kalashnikov:

Quote

Суть его заключается в том, что предварительный заряд тандемной боевой части пробивает отверстие в плитках реактивной брони без детонации содержащегося в них заряда. Этим не только обеспечивается проникновение в образовавшееся отверстие основного заряда, но и защита гранатомётчика от взрывной волны и осколков при стрельбе с близкого расстояния.

Explosive used in 4S23  has improved sensitivity in comparison with 4S22. It might explain why Relikt is claimed to be very effective against tandem RPGs.

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4 hours ago, J.J.S. said:

This lower part is quite heavy and will move with lower velocity than upper plates. Moreover these mounting beams will additionally slow it down. That's why such movement shouldn't be efficient against cumulative jet.

 

And that's why upper part in ERAWA has the same or higher weight than the lower part?

Learn some physics first at all.

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I have no idea where you learned physics to conclude that steel cuboid with 150x150x6 mm dimensions has the same or higher weight than steel cuboid with 150x150x10 mm dimensions, excluding the additional mass of cassete sides, screws and mounting beam. Then learn Gurney equations.

08b903e0ccbe1.png

 

 

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11 hours ago, J.J.S. said:

Vasiliy Fofano

he wrote it long time ago, so i don't know was he right or wrong

 

11 hours ago, J.J.S. said:

Fragment of article from russian miliary journal Kalashnikov:

russian magazines often write "something that we hear somewhere from someone"

 

how close you need to be that you will get damage from ERA block and not from explosion of grenade and tank itself 

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On 3/20/2020 at 11:12 PM, J.J.S. said:

I think that it's impossible to fully reduce reactive armour efficiency by simply increasing jet tip velocity (with copper liners it's also difficult to exceed 10 km/s) taking into consideration this fragment of "Evolution of ERA for light-armoured fighting vehicles" :

 

 

As I know it's the main way in modern SC warhed. Typical explosive fill and HHS plates in ERA are to sow  to disturb jet tip. And jet tip is responsible for most penetration posibilities...

bk6awUs.png

. Tandem RPGs  like Panzerfaust 3-T, PG-7VR (russian ATGMs don't)  use non-initiating precursors to increase the safety of infantryman using them against tanks with

ERA at short ranges.

IMHO the reson was diffrent in case german PzF-3. Thay had started developed PzF-3 in 1978(!) and first prototypes went in1982-1983 and trials in 1985. But first production series where from 1989 but it take to service in german army in 1992. All dalay was due to 2s21 tests and abilities. And this precursor based on EFP style SC was developed to overcome thin ERA Kontakt 1 casette and reactive plates inside. And it works fine.

The "zonk" was after T-80U tests in  Germany and Swedish trials in 1992. So they changed precursor and it didn't work well against 4s22 and ERAWA-2. Co they changed againt to non-initiating SC (low granulate) and in 2005 serial Pz-3IT600 had new abilities and defeted ERAWA-2 without problem.

 

 

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13 hours ago, J.J.S. said:

I have no idea where you learned physics to conclude that steel cuboid with 150x150x6 mm dimensions has the same or higher weight than steel cuboid with 150x150x10 mm dimensions, excluding the additional mass of cassete sides, screws and mounting beam. Then learn Gurney equations.

 

And you don't even how thick are plates in ERAWA-2 and what is inside of them. :lol:

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On 3/23/2020 at 7:49 AM, Wiedzmin said:

how close you need to be that you will get damage from ERA block and not from explosion of grenade and tank itself 

On 3/23/2020 at 8:49 AM, Militarysta said:

IMHO the reson was diffrent in case german PzF-3.

 

Such explanation is also included in Dynamit Nobel Defence marketing brochure:

Quote

The Panzerfaust 3 with its high performing mono-shaped-charge warhead was enhanced by Dynamit Nobel Defence to become the Panzerfaust 3-T (T stands for tandem warhead). This performance improved variant was developed in order to be effective against combat vehicles with add-on reactive armour. The warhead of the Pzf 3-T is designed in such a way that the first of both shaped charges immediately penetrates the add-on armour without initiating the explosive contained therein. Less than one millisecond later, the main charge of the tandem warhead ignites and thereby immobilises the vehicle. The shooter therefore is not exposed to fragments thrown back from a reactive protection element.

For the same reason they developed CLARA ERA with composite plates instead of metal ones.

 

On 3/23/2020 at 8:49 AM, Militarysta said:

As I know it's the main way in modern SC warhed. Typical explosive fill and HHS plates in ERA are to sow  to disturb jet tip. And jet tip is responsible for most penetration posibilities...

However, almost all weapons with SC that have been designed for last 30 years still have warheads with precursor.  Modern ERA have improved reaction time, good example of this is russian 4S24 in comparison with 4S20.  

1536fe0a4a602.png

Moreover, thick passive plates placed in front of reactive armor can significantly erode jet tip and reduce its velocity. For example there is 50 mm of steel between ChSKW-34 layers in Duplet from Oplot-M hull and 25 mm in front of 4S22 in T-72B ob.1989. Even 10 mm thick steel plate has noticeable effect.

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On 3/22/2020 at 7:04 PM, J.J.S. said:

This lower part is quite heavy and will move with lower velocity than upper plates. Moreover these mounting beams will additionally slow it down. That's why such movement shouldn't be efficient against cumulative jet.

 

The last statement does not stand for itself. Firstly, AFAIK term "shouldn`t be" is not used commonly in research papers on shaped charge vs ERA. Secondly, ERA bricks of ERAWA family already proved to work vs cumulative jet, and it`s efficiency was not a matter of doubts.

From what is known about ERA-jet interactions, rear flyer plate (that one that is chasing the jet) is more important than forward flyer plate. It is good when rear flyer plate is thick, because that means more material get into jet trajectory. It is good when ERA is sloped at last 60 degrees, because it gives more efficient use of movement of flyer plates. In case of ERAWA those conditions are met, to some degree. Another very important condition is velocity of back flyer plate - should be as high as possible, to extend the time of interactions with jet. ERAWA's rear flyer plate is probably slower than forward. But is was already said that ERAWA-2 was still quite good vs some tandem warheads. It is not big surprise that '80s/'90s development is not good enough vs more modern and more potent shaped charges.

 

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