JANE'S DEFENCE WEEKLY - JUNE 22, 2005
RUAG exploits new warhead technology
PAOLO VALPOLINI
JDW Correspondent Milan
RUAG's Defence Warhead Division demonstrated numerous new products in late May based on recently developed technology.
The new technology, which involves hollow-charge warheads based on a variable thickness molybdenum liner, has allowed RUAG to produce warheads that maintain optimal performance even if their desired stand-off distance (the distance between the target armour and the warhead detonation point) is not precisely respected, with the perforation remaining similar to results obtained where the stand-off distances are from three to five times the length of the charge diameter. Using this technology, RUAG charges can fully exploit almost all of the liner mass and put it where it is most needed at a speed of 11.5-12 km/s.
Two products employing the new technology were shown in action, the first being a 146 mm diameter charge containing 2.9 kg of explosive that perforated about 1,500 mm of ballistic steel consisting of a series of 80 mm thick steel plates. The molybdenum jet generated a hole with a diameter of 18-20 mm through the whole target. Such a warhead is proposed for the upgrade of anti-tank missiles of former generations as well as for new weapon systems in this category.
Another test was conducted using an RPG-7 rocket-propelled grenade launcher equipped with a RUAG tandem warhead designed to ensure good penetration even against armoured vehicles equipped with explosive reactive armour. This warhead achieves a penetration in excess of 900 mm against rolled homogenous armour and has an increased range up to 250-300 m. Tested against a former Swiss Army Pz68 main battle tank, it penetrated the gun breech block and remained inside the tank; subsequent tests produced both an entry and exit hole.
A warhead for the M72 LAW based on insensitive explosive and with a penetration in excess of 500 mm has also been developed: the current version is based on a single charge while a tandem warhead will be available soon.

NTERNATIONAL DEFENCE REVIEW - AUGUST, 2005
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RUAG unveils two shaped-charge warheads
Neil Gibson
Two new shaped-charge warheads have been unveiled by the Swiss RUAG company: a molybdenum (Mo) lined 146 mm diameter (152 mm case) and the second a new and improved tandem copper-lined warhead for the RPG-7 weapon system.
The ability to defeat heavily armoured AFVs relies on two main technologies: shaped charges - also know as the Monroe or Neumann effect - and that of pure Kinetic Energy (KE) attack. The use of pure KE attack is not used in most guided and shoulder-launched anti-armour weapons at present, mainly due to the necessary velocity, inherent high complexity and potential lethality to an unprotected firer. Shaped charges, on the other hand, can be thrown - even hand-placed - and can still defeat heavy armour. In this case the energy required to penetrate the target comes from the explosive contained within the munition, not the munition's velocity.
This is accomplished by using the explosive to collapse a hollow lined cavity (normally metallic) into itself, forming a hypersonic jet of material which pushes its way through the target.
RUAG's compact 146 mm PBXW-11 filled warhead consists of an aluminium alloy case with a Mo elliptical shaped liner. Its PBXW-11 filling is a relatively insensitive pressed plastic bonded explosive (PBX) containing HMX. The warhead has a central detonator well, the detonation wave being directed to the periphery of the charge via RUAG's waveshaper material PEGAB (PolyEster with GlAssBubbles). In a series of radiographic tests, the jet tip velocity (Vtip) reached around 11.5 km/s, achieved through a combination of the liner shape, its thickness, initiation mode and material. The Mo liner, although difficult to fabricate, more costly and having a lower dynamic ductility, has a higher bulk speed of sound which allows for a higher liner collapse velocity and hence jet velocity. Penetration is also improved as Mo possesses a higher density in comparison to copper, 10,280 to 8,920 kg/m3. For the demonstrations at RUAG's range in May (2005), the warhead was placed at 5.5 cone-diameters (CD) from a target array consisting of 22, 80 mm-thick RHA plates. The detonation of the charge resulted in the perforation of 17 plates and the lodging of the jet remnants some distance into number 18, an approximate penetration of some 10 cone diameters (1.45 m), with the average hole diameter through the plates by approximately 20 mm.
The new tandem RPG-7 warhead, unlike the previous firing, was a full system test. The launcher was at a distance of by approximately 75 m to the target. The target was a Swiss Pz68 tank, aligned so the round impacted its side. The warhead consists of two shaped charges: a small precursor charge (approximately 30 mm diameter); and the main charge (100-112 mm). Both were copper-lined and with either a PBXW-11 or LX-14 filling. No details were given of the liner profile, initiation mode, or whether RUAG's FORCE-HAMMER shock decoupling technology was used. In static tests the warhead is capable of penetrating >900 mm of RHA after second generation ERA. The dynamic firing resulted in the round striking the centre of the tank, approximately 20 mm below the turret, the jet passed along the top of the hull armour, ripping it open, then passed through the turret ring and embedded itself in the main gun's breech block. Total penetration depth was not disclosed, but this hit would have certainly resulted in an operational kill, as the main gun was out of action.