On the vibration test of ship hull during the sea trials and the vibration acceptance criteria

Abstract

Ship vibration becomes a great concern in the design, construction and operation of the vessels. In shipbuilding industry, excessive ship vibration during operation can occur by several excitation sources. In general, these major sources are the low-speed diesel main engine, the propeller, the auxiliary machinery, the supports, the HVAC...and ones during operation.  Excessive ship vibration is to be avoided for ship strength, passenger comfort and crew habitability. Hence, to follow vibration control procedures both in design stage and testing stage with insight and good judgment is quite essential for the shipyards. Besides, the control of maximum vibration levels of ships must be strictly approved by main classification societies before their first operation.

In Vietnam, ship vibration analysis is rarely aimed at the confirmation of the many design considerations. As the result, the evaluation and the solution on ship vibration are not well mentionned at most new-building ships. Without this mention, ultimately serious problems, involving great cost in correction efforts, may not be avoided. This research aims at a ship vibration test procedure including the measurement with data processing and analysis. That serves as a prediction tool to fix the vibration problems at the domestic shipyards