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av8rmongo wrote: Less than ten hours after posting my concern GHQ looked into the problem and sent me an e-mail to help resolve the issue.l

av8rmongo wrote:Just an update on one more reason why GHQ still gets my vote (and money). Less than ten hours after posting my concern GHQ looked into the problem and sent me an e-mail to help resolve the issue. Thanks GHQ for the excellent customer service!

Paul

av8rmongo wrote:GHQ responded that the pack were mispacked and the ratio should be 4 Command and 1 Ambulance. If you have packs that are incorrectly packed then contact GHQ.

Paul

WEAPONS AND EQUIPMENT

Date Posted: 25-Jul-2005

INTERNATIONAL DEFENCE REVIEW - AUGUST 01, 2005
Problems with Stryker's slat add-on armour

R M Ogorkiewicz

A recent US Army report prepared by the Center for Army Lessons has concluded that the slat add-on armour fitted to the Stryker 8x8 armoured vehicles operating in Iraq has proved effective against only about one half of the rocket-propelled grenades fired against the Strykers by the insurgents.

Although disappointing for the US Army, which has invested so much in the Strykers, it is not altogether surprising that the slat armour is not always effective given its nature, which is widely misunderstood.

The most common misconception about slat armour is that it is a kind of space armour that sets off RPG-7 grenades away from the hulls of the Strykers, greatly reducing their armour penetration. This view ignores the fact that, in order to reduce the penetration capability of RPG-7 grenades to the level at which they could not perforate Strykers' hulls, they would have to be detonated more than 1 m from the vehicles.

But even at a standoff of 900 mm, RPG-7 grenades can still penetrate 80 mm to 90 mm of rolled homogeneous steel armour (and average 320 mm of penetration at optimum standoff), whereas the standoff built into slat armour is only 10 in (254 mm). Slat armour cannot therefore detonate the grenades sufficiently far from Strykers' hull armour to prevent it being perforated, in spite of it being augmented by IBD's MEXAS ceramic add-on armour - although it might reduce the cone of spall fragments.

Nevertheless, it is claimed that the function of slat armour is "to detonate RPGs before they can reach the vehicle's armour and penetrate it", to quote but one defence journal. In fact the opposite is the case: slat armour is intended to prevent the detonation of the grenades.

What slat armour is designed to do is based on a particular feature of RPG-7 grenades, which is that their nose consists of two concentric cones that form part of the electrical circuit between the impact sensor at the tip of the nose and the fuze located behind the shaped charge. If a grenade impacts a target so that the sides of the nose hit it before its tip, the fuze is short- circuited by the concentric cones being crushed and contacting each other, as a result of which the shaped charge is not detonated.

To achieve this the slats are set 2.5 in apart, which is less than the diameter of the RPG-7 grenades. In consequence, if a grenade flies into the gap between slats, one side or the other of its nose will hit a slat and the shaped charge will not be detonated for the reasons already given.

However, instead of flying straight into the gaps between slats, some grenades are bound to first hit the edges of the slats, detonating their shaped charges, with serious consequences for the vehicles that the slat armour is intended to protect. Moreover, most grenades are unlikely to fly exactly parallel to the slats but instead to hit them at an angle when they can present an area considerably greater than their 0.25-inch thickness would indicate, which again is likely to increase the chances of the grenades' shaped charges being detonated.

A similar effect is being achieved by the insurgents who are reputed in some cases to have added discs to the tips of the grenades, enlarging their impact area and consequently increasing their chances of being detonated by the slats. What is more, some of the RPG-7 grenades that are not of Russian origin are reported not to use concentric cones as part of their fuze system so that crushing of the sides of their noses does not necessarily disable them.

All of this indicates that there are serious shortcomings to slat armour being used as protection against RPG-7 grenades, the net effect of which has been highlighted in Iraq.