The mechanical effects of underground nuclear explosions in rock salt are discussed concerning the generated wave parameters and the dimensions of the regions of irreversible deformation of the medium i. e. the cavity volume, the size of the pulverized zone and the ejection crater. Tabulated results of one Soviet and two American (Salmon and Gnome) explosions are presented. See also English translation in Sov At Energy v 30 n 1 Jan 1971 p 35-40