Shore power connection for offshore vessels - Measured noise reduction in port and dock

Abstract

The presentation will summarize measured noise reduction for drilling, pipelay and offshore support vessels due to shore power connection. The noise level at office or storage building in distance of 100-250 m from the vessels has been registered continously through days and nights. Noise levels at nights without and with shore power connection has been compared. A drilling vessel had Lw 110 dB and a noise reduction due to shore power connection of 18 dB. A pipelay vessel had Lw 105 dB without shore power, and a noise reduction of 15 dB due to the effect of shore power. Both drilling and pipelay vessel seem to have Lw of 90-92 dB with shore power connection. Two different offshore support vessels have also been measured with sound power level Lw of 107 dB and 100 dB. The noise reduction with shore power connection is 13 dB for the first and 6-7 dB for the latter. With shore power connection, both offshore suppert vessels have Lw of 94 dB. The sound power level with shore power connection seems to be limited by the fact that ship noise level from ventilation and fans seems to be the same.