Singing Propellers

The causes of singing of propellers of ship and the characteristics of noise produced are discussed with data from a case study. Five frequencies of singing were observed at 50 Hz, 152 Hz, 250 Hz, 340 Hz and 458 Hz depending on the state of the propeller. The marine fouling has profound influence both on frequencies and noise levels of singing. The airborne noise produced by the singing propellers has deleterious effects on human habitability and working efficiency and may even cause damage to hearing. Some remedial measures for elimination of singing are suggested