Accession Number : ADA017076

Title :   Trends in Merchant Shipping (1969-1980),

Corporate Author : TETRA TECH INC SAN DIEGO CALIF

Personal Author(s) : Ross,Donald

Report Date : 15 APR 1975

Pagination or Media Count : 96

Abstract : This study of merchant shipping trends has been inspired by the need of the underwater acoustics community to understand trends in measured low-frequency deep-ocean ambient noise levels; and, by the desire to be able to predict future levels. It is being given wider distribution because of the interest of other groups in the subject. It must be pointed out that most of the numbers quoted are estimates, or rounded-off values; and, that in acoustics one deals with numbers on a logarithmic scale, and exact values are not necessary. The reader should also be warned that some of the divisions of ships into categories do not conform to those usually used in the marine industry, but rather are intended to better serve the purposes of acoustic studies.

Descriptors :   *Ship noise, *Merchant vessels, Ambient noise, Underwater sound, Low frequency, Deep oceans, Forecasting, Container ships, Cargo ships, Tankers, Fisheries, Marine engines, Offshore drilling, Petroleum industry, Estimates, Statistical analysis, Classification, Engine noise, Velocity, Small ships, Horsepower, Predictions, Background noise, Extremely low frequency, Statistical data

Subject Categories : Marine Engineering
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE