Trans RINA, Vol 157, Part A3, Intl J Maritime Eng, Jul-Sep 2015
applied to passenger cabins or other passenger spaces, except insofar as such spaces are work areas, in which case they remain within the scope of the Code.
The set noise level limits are designed to ensure that seafarers will not be exposed to an Lex [25] exceeding 80 dB(A), i.e. within each day or a 24-hour period the equivalent continuous noise exposure would not exceed 80
dB(A). In spaces with sound pressure levels
exceeding 85 dB(A), suitable hearing protection should be used, or time limits for exposure should be applied to ensure that an equivalent maintained [4].
level of protection is
Table 2. Noise level limits in bridge and machinery spaces [3] and [4] Designation of rooms and spaces
New Code
1,600 up to 10,000 GT
Work spaces (in dB(A)) Machinery spaces permanently manned
Machinery spaces not permanently manned
Machinery spaces
Machinery control rooms
Non-specified work spaces
Navigation spaces (in dB(A)) Radio rooms Look-out posts
Accommodation spaces (in dB(A)) Cabins and hospitals
Mess rooms Recreation rooms
Open recreation areas
Offices 110 Workshops 85 110
75 75 85
85 85
60 70
60 70
60 55 65
65
75 75 65
60
75 85
90
60 70
60 60
60 65
65 75
65
Table 2 shows that the recommended noise levels are maintained with two exceptions: non-specified work spaces, in which the maximum noise levels are reduced by 5 dB, and in machinery spaces (in which the distinction between
permanently manned spaces has been removed), representing an increase of 20 dB.
The limits have not been modified in navigation spaces, ranging from 60 dB in radio rooms and 70 dB in navigating bridge wings. Hence, the auditory
stress
suffered by bridge and radio staff is much lower than that suffered by engine room staff. The remaining spaces continue to have the previous noise level limit.
≥10,000 GT
Old Code
90 110 There is an improvement in the limit in the
accommodation spaces of vessels of 10,000 GT and above, being reduced by 5 dB compared to the levels of the previous code, except in recreation rooms, where the level is maintained at 75 dB.
The new code will, in general, be mandatory, though some parts will not: for instance, those parts referring to existing vessels of 1,600 GT and above, and new ships of below 1,600 GT, operating conditions in port, noise exposure limits, insulation materials and the selection and use of hearing protectors, in addition to all appendices except for the first one.
the
The new code establishes that a noise survey report is to be made for each ship and that this report is always to be carried on board.
3.3 NATIONAL REGULATIONS
The one currently in force is R.D. 286/06 [6]. Although initially excluded on-board staff, the Transitional Provision established that it is to be applied to these workers from November 2011. Although this legislation is better than nothing, it only makes reference to daily noise exposure limits and the values are quite consistent with IMO regulations.
3.4 CLASSIFICATION SOCIETIES’ (CS) REGULATIONS ON NOISE
In addition to international standards and national
regulations, CS have included in their Regulations a notation aimed at assessing comfort with respect to noise and vibration on board.
The following Noise Standards are frequently used by CS:
IMO Res. MSC 337(91) - "Adoption of the code on noise levels on board ships.
ISO 2923:1996, "Acoustics - Measurements of noise on board vessels.
ISO 140, in particular Part 4 (Field measurements of airborne sound insulation between rooms) and Part 7 (Field measurements of impact sound insulation of floors).
permanently manned or not
ISO 717 (Rating of sound insulation in buildings and of building elements), in particular Parts 1 (Airborne sound insulation) and 2 (Impact sound insulation).
Although some of these Standards have recently been revised, the CS are still using the previous ones.
Of the ten companies that are members of IACS (International Association of Classification Societies), the most important worldwide are: American Bureau of Shipping (ABS), Bureau Veritas (BV), Det Norske Veritas (DNV), Germanischer
Lloyd (GL), Lloyd's Register (LR) and Registro Italiano Navale (RINA). ©2015: The Royal Institution of Naval Architects A-137
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