Abstract: Measuring parameters of ship motion, such as natural rolling/pitch period, steady inclination and mean draught, is difficult with traditional methods because the motion is limited by mooring forces from bollards and breasting forces from fenders. Besides, the motion is intermittently excited randomly by the operation of container handling. These parameters are measured indirectly by installing dynamic inclination angle sensors on the cranes of the shore-bridge. The waveforms of free inclination without berthing constraints are measured by means of the installation on the bridge when ship is excited by container handling, taking the advantage of the linear relationship between damping moment and angular speed for rolling/tilting of small amplitude. The motion parameters of the ship are identified by processing the measurements form the sensors. A few tools are used in the processing, such as clipping and moving average median filter method, the method for segmental identification of parameters of decaying sinusoidal curve, as well as the differential equations of damped oscillation. The concept is simulated and tested on site. The method can measure real time states of ships and there is potential to protect container ships in the process of loading/unloading.