In the present paper, a modelling approach for the simulation of the overall ship propulsion plant is presented. A cycle mean value model with differential equations for the calculation of the engine crankshaft and turbocharger shaft speeds is used for the modelling of the main engine of the vessel. The ship shafting system is modelled using the power balance and its efficiency. In order to calculate the propeller thrust and torque, the polynomials for the propellers of the Wageningen B type are used. In addition, the ship velocity and the movement along its longitudinal axis are also calculated using the differential equation describing the ship surge dynamics. The mathematical equations of the ship propulsion plant model are implemented and solved using the computational environment MATLAB Simulink®. The model was used for the simulation of the propulsion plant of a merchant ship under various operating conditions and the derived results are presented.