[en] The forces are discussed exciting vibrations of transversely and obliquely by-passed components of nuclear equipments, such as tube bundles, valve stems, thermometric tanks, etc. Forces are considered which originate in the process of the periodical vortex shedding from the by-passed bodies. The process of vortex shedding is characterized by the Strouhal number. Using this criterion it is possible to apply the results of measurements from a model to a geometrically similar body. The experimental course and empirical formulas for the Strouhal number S are given for transversely and obliquely by-passed cylinder, a transversely by-passed cone, a transversely by-passed plate and a quadrangular prism, a transversely by-passed truncated prism in dependence on the number of edges and its orientation in the flow. (B.S.)