In late 1992, the Polish Military Institute of Armament Technology (WITU) stated that it had developed and tested two types of Explosive Reactive Armour (ERA), ERAWA-1 and ERAWA-2.

The ERAWA-1 has a single layer of ERA blocks while the ERAWA-2 has two layers for increased battlefield survivability.

The ERAWA system can be fitted to MBTs such as the T-72. A T-72 MBT fitted with ERAWA-1 blocks has its turret protected by 108, the hull by 118 and each of the two side skirts by 84 blocks. This gives the vehicle a total of 394 blocks with the total area of the tank protected being about 9 m2.

Compared with the ERA system developed by the Russian Federation and Associated States (CIS), the Polish ERA blocks are of a different shape and design. RFAS blocks are oblong whereas the new Polish blocks are more square in shape with a small attachment hole at each corner.

According to the WITU, the installation of the ERAWA-1/ERAWA-2 armour package reduces the penetration capability of a shaped charge round by 50 to 70 per cent, this depending on the incidence angle of the shaped charge jet on the armour block.

The Polish armour package is insensitive to 7.62, 12.7 and 14.5 mm Armour-Piercing (AP), Armour-Piercing Incendiary (API) and High Explosive (HE) small arms fire as well as fragments of 20 to 30 mm cannon rounds.

Trials have shown that only the ERAWA block hit by a High Explosive Anti-Tank (HEAT) round will be initiated while the adjacent blocks are not initiated, although there is a possibility that they may be damaged or torn off.

The blocks and their associated attachments have been designed so that they can be placed very close to each other. On a flat surface it is claimed that up to 95 per cent of the surface can be protected while on convex surfaces, such as that of the MBT turret, between 80 and 90 per cent can be protected.

Although designed originally for installation on MBTs, the ERAWA packages can also be installed on other types of vehicle including infantry fighting vehicles as well as static pillboxes and other installations that may be attacked by weapons fitted with HEAT warheads.

According to the Military Institute of Armament Technology, their ERAWA provides the following level of protection:

(1)95 to 100 per cent protection against HEAT projectiles of the low piercing type (300 to 350 mm) such as the RPG-7

(2)65 to 70 per cent protection against HEAT projectiles and rockets of the medium piercing type (460 to 600 mm) such as the AT-4 anti-tank weapon or 125 mm BK-14M HEAT projectile

(3)90 to 100 per cent protection against EFP (Explosive Formed Projectiles) with a calibre of 100 mm

(4)Full resistance against detonation after being hit by low and medium calibre ammunition, hand and mortar grenade fragments.

(5) Full resistance against detonations caused by the burning of high temperature (up to 3,000° C) materials such as napalm.

Under field conditions, the crew can install an ERAWA system covering an area of 8.5 m2 in about 8 hours or a special design protecting 5.9 m2 in about 2 hours.

In addition to being fitted with ERAWA packages, the T-72 was also fitted with a bank of six 81 mm smoke grenade dischargers either side of the turret in an inverted L arrangement and, below these, were further six unidentified sockets. Either side of the turret was a cylinder which is a laser warning device with additional laser warning devices being positioned on either side of the turret at the rear giving virtual 360° coverage. Details of the Polish PEO laser radiation warning system are given in the Threat warning systems section of this book.

Production. It is understood that one version of the ERAWA is installed on the recent Polish PT-91 MBT which is now in service with the Polish Army. This is a further development of the Russian T-72M1 MBT which was manufactured under licence in Poland for many years.