Torsional vibration analysis
The investigation of low power output of the 6RTA58 main engine's unit 6 revealed, that the crankshaft had slipped by 96°CA. Consequently, referred to torsional vibration calculation based on data from new building, the operation needed to be restricted.
Tekomar was engaged to evaluate the torsional vibratory stress of the shaft line by measurement, and to comment the results. The found level was below the calculated values, well within admissible limits. Tekomar recommended to cancel the newly imposed operational restrictions.
The results were submitted to classification society and resulted in lifted restrictions allowing the ship owner to operate his vessel safely without additional barred speed ranges.