The article presented is devoted to the problems of resistance of unprotected structures of process equipment such as large storage tanks, and tall and slender pressure tanks under impact loads. The subject of the study is a qualified estimation of the survivability of such cylindrical shell structures when hit by a flying object. The results may be used for the estimation of the safety factor of these structures in early project and construction stages, and will be of value when deciding whether the resistance and hence the safety of the structure is sufficient for a given type of processed or stored agents (which are mostly toxic chemicals, flammable and explosive liquids and gases, liquefied gases) or whether it is necessary to design a more resistant and, of course, more expensive structure.