- With reference to noise levels in ships:
(a) describe the recommended maximum periods of time for personnel employed on watchkeeping duties within enclosed machinery spaces;(6)
(b) explain why these recommendations have been made;(2)
(c) state the permitted noise level at which hearing protection is:
recommended;(1)
(ii) mandatory.(1)
(a) Recommended maximum periods of time for personnel on watchkeeping duties in enclosed machinery spaces (6 marks)
According to IMO/ILO guidelines (based on exposure limits):
- 90 dB(A): up to 8 hours.
- 95 dB(A): up to 4 hours.
- 100 dB(A): up to 2 hours.
- 105 dB(A): up to 1 hour.
- 110 dB(A): up to ½ hour.
- 115 dB(A): up to ¼ hour.
(Exposure to levels above 115 dB(A) is not permitted without special protection.)
(b) Why these recommendations have been made (2 marks)
- To protect seafarers from noise-induced hearing loss caused by prolonged exposure.
- To ensure that seafarers can continue safe watchkeeping duties without fatigue, loss of concentration, or long-term health damage.
(c) Permitted noise levels for hearing protection (2 marks)
- Recommended: at 85 dB(A) and above.
- Mandatory: at 90 dB(A) and above.