The measurement of underwater noise radiated by dredging vessels during aggregate extraction operations


Theobald, P.D., Robinson, S.P., Lepper, P.A., Hayman, G., Humphrey, V.F., Wang, L. and Mumford, S.E. (2011) The measurement of underwater noise radiated by dredging vessels during aggregate extraction operations. In, Fourth International Conference on Underwater Acoustic Measurements, Technologies and Results, Kos, Greece,

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Description/Abstract

The total marine aggregate extracted from the seabed in UK waters can exceed 20 million tonnes each year, and there is a need to understand the noise generated during the extraction process in order to evaluate any potential impact on the marine environment. For aggregate extraction, the type of vessel used is a trailing suction hopper dredger, which lowers a drag head and suction pipe to the sea floor to extract the sand or gravel, depositing it in a hopper on the vessel, whilst returning unwanted material and water over the side of the vessel. There are a number of potential noise generation mechanisms during this type of dredging activity. This paper presents the results of underwater noise measurements for six different dredgers measured in three locations around the UK, with aggregate type varying from sand to coarse gravel. One vessel was measured in two different areas with different aggregate types. The methodology used to derive the source level for the dredgers is described, and the results of an investigation into the origin of the radiated noise are given. Measurements were made at frequencies up to 100 kHz. Noise levels are shown for the same dredger under different operational modes, illustrating that the noise output is partially dependent upon the mode of operation and the aggregate type being extracted.

Item Type: Conference or Workshop Item (Paper)
Additional Information: Page 763-769 of the proceedings made available to all registered participants on the first day of the conference.
Keywords: source level, noise, dredging, ansi s12.64.
Subjects: Q Science > QC Physics
T Technology > TK Electrical engineering. Electronics Nuclear engineering
V Naval Science > VM Naval architecture. Shipbuilding. Marine engineering
Divisions: Faculty of Engineering and the Environment > Institute of Sound and Vibration Research
ePrint ID: 195857
Date Deposited: 31 Aug 2011 08:42
Last Modified: 27 Mar 2014 19:45
URI: http://eprints.soton.ac.uk/id/eprint/195857

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