STUDY OF AIRBORNE NOISE FROM SHIPBOARD MACHINERY

A comprehensive survey of noise in combatant ships shows that airborne sound levels generated by machinery items are above specifications in several shipboard spaces. Although absolute noise evaluation of individual machines is difficult while underway, dockside tests can be used to define such characteristics for most such items. These characteristics are discussed and compared, and total environmental noise conditions are evaluated on individual and statistical basis for various machinery and personnel spaces. Existing noise conditions at sea and dockside are compared to applicable habitability criteria, together with an analysis of reported effects of sound on personnel. Based upon the broad survey of equipment and environmental noise characteristics discussed, it is possible to generalize upon approaches and techniques for controlling airborne noise aboard ship. In addition, the applicability of specific treatments are discussed for several noisy items, together with predictions and data on the effectiveness of such treatments. Legibility of this document is in part unsatisfactory. Reproduction has been made from best available copy.