 Reactive armour can be defeated with multiple hits in the same place, as by tandem-charge weapons, which fire two or more shaped charges in rapid succession.Without tandem charges, hitting the same spot twice is much more difficult.The idea of counterexplosion ("kontrvzryv" in Russian) in armour was first proposed by the Scientific Research Institute of Steel (NII Stali) in 1949 in the USSR by academician Bogdan Vjacheslavovich Voitsekhovsky
(1922–1999).