[en] The results are shown of measuring pressure drop due to friction, velocity field and shear stress distribution around the wetted circumference in a rod bundle with the displaced central rod. The measurement was conducted on a 19-rod aerodynamical model with the Reynolds number Resub(k)=137 400. The friction pressure drop coefficient was found to be little dependent on the central rod displacement. The dependence is given of an uneven distribution of shear stresses on rod displacement. The applicability is confirmed of the universal law of the distribution of velocity component normal to the wetted surface. The region of the rod displacement effect on hydrodynamic characteristics does not exceed the immediate neighbourhood of the displaced rod. In damaged rod lattices the secondary flow effect is markedly felt on the transverse momentum transfer. (J.F.)