00000nam 2200000zi 4500 9.942993 CaOODSP 20240918115214 m o d f cr bn||||||||| 240909e198512##nscd ob f000 0 eng d CaOODSP eng rda CaOODSP eng eng fre n-cn--- D68-21/10-1985E-PDF Leggat, Lennox John, 1949- author. Analysis of the underwater noise of CCGS John A. Macdonald / L.J. Leggat ; approved by T. Garrett. Dartmouth, N.S. : National Defence, Research and Development Branch, Defence Research Establishment Atlantic, December 1985. 1 online resource (iii, 14 pages) : graphs. text txt rdacontent computer c rdamedia online resource cr rdacarrier Technical memorandum ; 85/223 Digitized edition from print [produced by Defence Research and Development Canada]. Includes bibliographical references (page 12). "A sound range trial with the Canadian icebreaker CCGS John A. MacDonald was carried out on the Halifax Sound Range to provide data for the "Marine Arctic Transportation Sound Physics and Responses of Marine Mammals" Project. The ship underwater noise was measured for a number of ship speeds and propeller operating conditions. Underwater radiated noise results are reported for the conditions tested in octave-bands in terms of the equivalent source mean spectrum level over the frequency band of 8 Hz to 32 kHz. A comparison is drawn between the measured levels and levels predicted using an empirical technique. Results show that, in general, measured noise levels exceed predicted levels by between 6 and 8 dB"--Abstract, page ii. Includes abstracts in English and French. Icebreakers (Ships) Canada Noise. Propellers Noise. Brise-glaces Canada Bruit. Hélices Bruit. Defence Research Establishment Atlantic, issuing body. D.R.E.A. technical memorandum ; 85/223. (CaOODSP)9.941838 PDF 668 KB https://publications.gc.ca/collections/collection_2024/rddc-drdc/D68-21-10-1985-eng.pdf