Kontakt-5 is a type of third-generation explosive reactive armour originating in the Soviet Union. It is the first type of ERA which is effectively able to defeat modern armour-piercing fin-stabilized discarding sabot (APFSDS) rounds.
Introduced on the T-80U tank in 1985, Kontakt-5 is made up of "bricks" of explosive sandwiched between two metal plates. The plates are arranged in such a way as to move sideways rapidly when the explosive detonates. This will force an incoming kinetic energy penetrator or shaped charge jet to cut through more armour than the thickness of the plating itself, since "new" plating is constantly fed into the penetrating body. A kinetic energy penetrator will also be subjected to powerful sideways forces, which might be large enough to cut the rod into two or more pieces. This will significantly reduce the penetrating capabilities of the penetrator, since the penetrating force will be dissipated over a larger volume of armour.
The effectiveness of Kontakt-5 ERA was confirmed by tests run by the German Bundeswehr and the US Army. The Germans tested the K-5, mounted on older T-72 tanks, and in the US, Jane's IDR's Pentagon correspondent Leland Ness confirmed that "when fitted to T-72 tanks, the 'heavy' ERA made them immune to the depleted uranium penetrators of M829 APFSDS, fired by the 120 mm guns of the US M1 Abrams tanks, which were among the most formidable tank gun projectiles at the time." This is of course, provided that the round strikes the ERA, which only covers 60% of the frontal aspect of the T-72 series tank mounted with it.
Newer KE penetrators like the US M829A2 and now M829A3, have been improved to defeat the armor design of Kontakt-5. The M829A2 was the immediate response, developed in part to take on the new armor bricks. The M829A3 is a further improvement of this as well and designed to fight future armor protection methods.
As a response to the M829A3, the Russian army have designed Relikt, the most modern Russian ERA, which is claimed to be twice as effective as Kontakt-5 . It detonates on command before the round hits based on information from radar. It can be installed on T-72B and T-90 tanks and is being tested in the Leningrad Military District, although Relikt is not actually in service on any Russian tank.[1]
Kontakt-5 armour is employed by Russia and Ukraine.
Ideas have been drawn up for a new type of ERA called Kaktus which has been developed, although it has yet to be deployed.