The objective was to evaluate noise, vibration and acoustic insulation on a cable repair vessel named C/S Sophie Germain, located at Colombo dockyard, Sri Lanka. Measurements were conducted by NV Dynamics team in order to verify that the requirements of ISO, IMO and COMF class were met by the cable laying ship.
For the purpose of analyzing vibration, three uni-axial vibration transducers were used. The sensors were subsequently fixed onto an aluminum block in vertical, transverse, and longitudinal directions, the same was installed onto the ship's floor at each designated measurement point. The transducers were connected to a multi-channel data acquisition system, through which vibration data was recorded for a minimum of 2 minutes at each location.
All doors and windows were shut during the noise and acoustic insulation measurements. To determine acoustic insulation, the ship was rested in anchored condition at the quay. A certified sound source was positioned at a minimum distance of 1 meter from any corner and away from the shared partition within the source room. Pink noise was utilized to stimulate the designated room space, ensuring the creation of a uniform diffuse field. The Sound Level Meter (SLM) microphone with windscreen was utilized for the noise assessment that was carried out for a minimum of 20 seconds at all specified locations under both operating conditions of the ship.
Using SIEMENS data processing suite, large size data analysis and its interpretation was carried-out to arrive at a number of data outputs. With appropriate inferences, the technical report on the findings were submitted to the customer.