Abstract: In this paper, two formulas for calculating the forces acting on the boom put forward by Prof. L. E. Pashevsky and Master S. Y. Muchinic and their adaptability to conditions of high-speed flow and deep water are discussed.Based on theoretical researches and hydrotechnical experimens, this paper gives thepile of logs in the boom a new conception which regards the pile of logs as a floatingbody composed of floating units and characterized by its structure and shape. Onthe basis of the theory of hydrodynamic resistance, this paper also gives a newformula for calculating forces acting on the boom: P = A·b3·h3·V2·F(P).