Rotary cutting apparatus has a frame, a first rotary device and a second rotary device. Each of the first and second rotary devices has a shaft concentrically arranged about a rotational axis and a drum and are arranged in the frame in such a way that said first and second axes are substantially horizontal and substantially in the same vertical plane. A pair of bearing housings is arranged on either side of each of the drums. A first pair of bearing housings is movable relative to the frame in a transverse direction to the first rotational axis by means of a force means. Means is provided for passive vibration attenuation of at least the first shaft, the means being able to reduce vibrations due to impacts of the first drum in relation to the second drum.