Estimates of acoustic noise generated by supply vessels working with oil-drilling platforms

The paper presents results on spatial measurements of acoustic noise generated by two types of tugs during their movement near the Molikpaq platform and in a dynamic positioning mode during operation with the PA-B platform. Based on the results of these measurements with the aid of simulation and preliminary research of the loss function conducted on acoustic profiles spanning from the platforms to the nearshore Piltun gray whale summer—fall feeding area, the spectra of equivalent point sources are constructed, which make it possible to construct the 1/3-octave spectra of anthropogenic noise at any point of the western profile and estimate the value of their level in a given frequency band with an accuracy of up to 2 dB. Field measurements have shown that in the dynamic positioning mode, the tugs generate 10 dB more noise than during movement; in fact, a diesel electric tug in both modes produced approximately 5 dB less noise than a diesel tug.