Energy-saving ducts (ESD) attract much attention because of their significant ability to increase ship efficiency. Along with the issues of hydrodynamic interaction with the propeller and the hull, hydrodynamic loads on ESD and especially unsteady loads are of interest for ESD strength assessment. The paper presents complex experimental and numerical investigations performed to study unsteady pressures and forces acting on ESD due to wake nonuniformity and turbulence. The computations were performed using a hybrid URANS/LES approach. Force and pressure measurements with a high temporal resolution were carried out in the Potsdam ship model basin. Both numerical and experimental studies revealed strong unsteady pressure fluctuations and high oscillating forces on the duct which are increased by the propeller suction. The root mean squares of the fluctuation of axial, transverse and vertical forces are, respectively, 1.5, 0.8 and 0.4 percent of the total propeller thrust. The results can be useful for the prognosis of structural problems for energy saving ducts.