Explosively Formed Axe (EFA)

[Kunal Biswas]

The system, known as Explosively Formed Axe (EFA), has two versions–light and heavy–which have been under development for several years by an industry team led by the Explosia Pardubice Company and the VTUO Brno division of the state-owned military repair plant VOP-026 Seternberk. Around two years of development will be required to produce an operational system.

Integration is under way in the Czech Republic of an indigenously developed the active protection system aboard an obsolete OT-64 8x8 armoured personnel carrier, in preparation for live system-level trials against rocket-propelled grenades (RPGs) and anti-tank missiles, with trials having been planned to take place in the latter part of 2009. A successful system may be adopted by the Czech Army to equip elements of its armoured vehicle fleet, including the 8x8 Pandur II, 4x4 Light Multipurpose Vehicle (LMV) or 4x4 Dingo 2.

Development of the APS began in the Czech Republic in 2006. It is a shared effort of an industrial team led by the Explosia Pardubice company (inventor and producer of Semtex explosives), working with the VTUO division of the state-owned military repair plant VOP-026 Sternberk, based in Brno. The research programme for tank protection was concluded by the end of 2008. Czech Army units on overseas missions generally only deploy with light-and medium armoured vehicles, and in addition to attacks involving blast mines, require protection against RPGs and improvised explosive devices (IEDs) generating explosively formed kinetic-energy penetrators (EFPs). The Czech Ministry of Defence therefore initiated a further project in 2007, aimed at providing an APS for these two categories of vehicle. This is being handled by a team that includes both Explosia Pardubice and VOP-026, supported by a top Czech technical university/institute, the CVUT of Prague.

Army Guide - EFA, Active protection system

 

[Damian]

Interesting design, at some point it looks similiar to German AMAP-ADS system.

 

[methos]

According to the internet it is using a linear shaped charge and having a central radar as sensor. Therefore it is not really comparable with AMAP-ADS.
A long time ago the U.S. also developed/designed a similar system also using linear shaped charges and a radar for scanning for threats. It was dubbed "Dash-Dot Device" and is somehow connected to the American T95 MBT (see Hunicutt's Abrams, p.106).

AMAP-ADS is not using linear shaped charges and does not use a centralized sensor unit, but a large amount of smaller passive wake up sensors. From the optical aspect, both got "countermeassure boxes", but the sensors between them are laking in EFA. Unless AMAP-ADS charges can be focused extremly accurate on the penetrator's tip (~20 - 30 mm typically), EFA will be more potent in terms of protection against KE rounds. The common critcsm on EFP/shaped charge based APS is that it enlarges the danger zone arround the vehicle. While the copper "jets" (line in linear shaped charge) ensures greater protection, this could lead to a greater amount of civilian losses in urban operations.

 

[militarysta]

Interesting design, at some point it looks similiar to German AMAP-ADS system.

there is nothing similiar betwenn AMAP-ADS and EFA It's like talking that BMW-5 is quite simillar to Skoda Octavia.

Czech EFA it's nothing new - it's child born from cooperation between:
a) Explosia
b) ECO
c) VTUO Brno (part of VOP-026 Sternberk)

EFA have two verison EFA-light and EFA-heavy (for tanks). Devolping EFA had started in 2006 and first test was done in 2009 , there aere two test known:
a) on OT-64 SKOT APC when EFA destroyed PG-7W granade (1m from APC)
b) on T-72M1 whit EFA who was shot by APFSDS:
-3BM15 (12:1)
-3BM42 (16:1)
-EPpSv-97 (20:1)

Czechs claim that EFA reduces APFSDS penetration capabilities ca about 30%. What is interesting - the best performace EFA achive vs. tungsten rods, not vs. old steel (alloy steel with something). On the internet there are drawings of the patent possible to download, and Czech financial report from the EFA developing study (for Czech MoD).

 

[militarysta]

. Unless AMAP-ADS charges can be focused extremly accurate on the penetrator's tip (~20 - 30 mm typically), EFA will be more potent in terms of protection against KE rounds.

?
As I known AMAP-ADS in "heav" version can just destroyed APFSDS penetrator - many years ago was some demo for military press members about AMAP-ADS capabilities, and there where shown x-ray photos whit APFSDS rod (penetrator) during the destruction process by AMAP-ADS. And in heavy version IMHO AMAP-ADS can destroyed penetators.

 

[methos]

As I known AMAP-ADS in "heav" version can just destroyed APFSDS penetrator - many years ago was some demo for military press members about AMAP-ADS capabilities, and there where shown x-ray photos whit APFSDS rod (penetrator) during the destruction process by AMAP-ADS. And in heavy version IMHO AMAP-ADS can destroyed penetators.

I have never seen such a photo... I allways though that it just changes the angle of approach so that the surface on which the kinnetic energy is distributed is increased by ~5 - 10 times. If it could destroy APFSDS then the claims from Rheinmetall/IBD would make more sense, but the question remains how should AMAP-ADS destroy KE ammo? A huge focused energyblast does not have much penetrative capability... but maybe it (very speculative) it is capable of increasing the stress inside the penetrator so that it breaks...
Do you know where I can find this photo?

 

[militarysta]

(...)

Well I had written about APS here:

Aktywne Systemy Ochrony (APS) � Gdzie zaczyna siÄ™ wojsko"¦
and there You have smth about AMAP-ADS. Yes, I know -in polish...

but the question remains how should AMAP-ADS destroy KE ammo? A huge focused energyblast does not have much penetrative capability...

The answer is: DIME (Dense Inert Metal Explosive)
It's not only very focus energy blast, but bast very "concentrated" by tungsten powder or even micro pellets. In fact target ~1m before target is hit by small tungsten wall whit Vmax few km/s,but after 3-5m this "wall" formed by tungsten powder "decays" and it's not dangerous for infanty. Key is very precision network of detonators - who are able to direct the DIME into the target.
Thats reson why AMAP-ADS in "heavy" wersin can destroy EFP whit Vmax 2km/s, and APFSDS whit Vmax 1,5-1,8km/s. And this all only about 1m before protected area.