2. Operate the crushing plant. 2.1 Carry out pre-start, start-up, run and shutdown procedures. 2.2 Select and modify the operating technique to meet changing work conditions. 2.3 Use dust suppression and extraction methods . 2.4 Conduct, control and monitor operations within the equipment limitations, maintaining crushing efficiency and ... during the process of its crushing coal. The record shows random oscillatory motion typical of a situation in which the eccentricity of a rotating shaft keeps chang ing. This is expected in a crusher as the centre of gravity of the coal mass changes arbitrarily within crusher chamber.