Synthesia AS, Research Institute for Industrial Chemistry (VUPCH) designs, develops and manufactures a wide range of special explosive products.

These products include low-energetic thermoplastic detonating cord, flexible linear shaped charges, thermoplastic sheet explosive, explosive rope charges for mobile land mine clearance systems, aircraft canopy severance systems and dynamic protection elements for armoured vehicles.

All of the company's plastic and flexible explosives are marked for pre-explosion detection according to the Montreal Convention and are easy to detect by means of detectors currently in service.

The dynamic protection elements (or Explosive Reactive Armour (ERA) systems as they are normally referred to) are key components of the dynamic protection systems for the modified T-55 and T-72 MBTs.

According to Synthesia AS, their construction provides protection against projectiles fitted with tandem High-Explosive Anti-Tank (HEAT) warheads. The explosive used in these dynamic protection systems meets requirements of insensitive munitions.

In addition to the normal sandwich type ERA, the company has also developed an ERA package in which the internal element consists of a series of inverted V-type elements.

While the actual explosive element used in the Czech Republic armour packages is manufactured by Synthesia AS, the VOP 025 Novy Jicin armoured vehicle facility is involved in the actual mounting system. The Czech company of Vyzkumny A Zkusebni Ustav PV 010 is also involved in these armour systems.

The explosive reactive armour system for the T-55, for example, comprises ERA boxes and panels attached to the glacis plate, both sides of the tank turret, left and right mud guards and the upper part forward and between the commanders and loaders hatches.

Extensive trials in the Czech Republic of a T-55A series tank fitted with an explosive reactive armour package showed the following:

(1) a 100 to 200 per cent increase in protection against hand-held anti-tank weapons and missiles of the shaped charge type whose penetration effect is more than 650 mm

(2) increase of 250 to 300 per cent in protection against shaped charge submunitions of the top attack type

(3) increase of 100 to 140 per cent against artillery shaped charge projectiles

(4) it was also evident that there was some increase in ballistic protection against subcalibre armour piercing projectiles.

When attacked by small arms fire of 12.7 mm or less, the explosive reactive armour is not activated and its design is such that if one box of explosive reactive armour is activated by a HEAT projectile the box either side will not be activated.

It is claimed that standard plate (P) type of explosive reactive armour is more effective against the higher angles of impact, while the so called wedge type (V) or cross (K) types are more effective at perpendicular angles of attack.

Production as required. It is expected that this ERA will be fitted onto upgraded T-72 series MBTs of the Czech Republic of the future.