Section
2 Noise
2.1 Assessment criteria
2.1.1 Where
a space is occupied by both passengers and crew, the more stringent
of the relevant requirements apply unless agreed between the Builder
and Owner and advised to LR.
2.2 Passenger accommodation and public spaces
2.2.2 For cabins bordering discotheques and similar entertainment spaces, the
deck and bulkhead sound insulation is to be sufficient to ensure that the maximum cabin
noise levels are not exceeded even when high external noise levels prevail. Noise from
entertainment spaces shall be considered as transient noise and should meet the
requirements stated in Pt 7, Ch 12, 2.6 Transient noise.
Table 12.2.1 Passenger ships - Maximum noise
levels in dB(A)
| Location
|
Acceptance Numeral
|
| 1
|
2
|
3
|
| Passenger cabins:
|
Standard
|
49
|
52
|
55
|
|
|
Superior
|
45
|
47
|
50
|
| Public spaces:
|
Excluding Shops
|
55
|
58
|
62
|
|
|
shops
|
60
|
62
|
65
|
| Medical centre:
|
50
|
55
|
60
|
| Theatre/auditorium
|
50
|
55
|
60
|
| Open deck recreation areas (excluding swimming pools and
similar)
|
67
|
72
|
72
|
| Swimming pools and similar
|
70
|
75
|
75
|
Note
1. The levels may be exceeded by 5dB(A)
within 3 m of a ventilation inlet/outlet or machinery intake/uptake on
open decks.
Note
2. The levels may be exceeded by 3dB(A)
in accommodation above the propellers for three decks above the
mooring deck.
Note
3. The levels for open deck recreation
areas refer to ship generated noise only. On open deck spaces the
noise generated from the effects of wind and waves can be considered
separately to limits agreed between the Builder and Owner and advised
to LR for the trial conditions.
|
2.2.3 Acceptance of noise levels greater than those specified in Table 12.2.1 Passenger ships - Maximum noise
levels in dB(A) may be considered where agreed between the
Owner and Builder at specification/contract stage. Not more than 20 per cent of the
passenger cabins, 30 per cent of the public spaces and 20 per cent of the crew cabins
should exceed the relevant noise criteria by more than 3 dB(A).
2.2.4 Acoustic insulation of bulkheads and decks between passenger spaces is to be
generally in accordance with the values of the weighted apparent sound reduction index
R'w as given in Table 12.2.2 Minimum apparent airborne sound
insulation indices, R'w
, calculated using ISO 717/1. See also
Pt 7, Ch 12, 2.2 Passenger accommodation and public spaces 2.2.6.
Table 12.2.2 Minimum apparent airborne sound
insulation indices, R'w
| Location
|
Acceptance Numeral
|
| 1
|
2
|
3
|
| Passenger cabins:
|
Standard
|
41
|
39
|
38
|
| Superior
|
45
|
42
|
40
|
| Cabin to corridor:
|
Standard
|
38
|
36
|
35
|
| Superior
|
42
|
40
|
37
|
| Cabin to stairway:
|
Standard
|
47
|
45
|
43
|
| Superior
|
50
|
47
|
45
|
| Cabin to public space (excluding
corridors/stairwells and discotheques):
|
Standard
|
52
|
48
|
48
|
| Superior
|
55
|
50
|
50
|
| Discotheques to
cabins
|
60
|
60
|
60
|
| Discotheques to
stairwells and public spaces
|
52
|
52
|
52
|
| Cabin to machinery
rooms and engine casing
|
55
|
53
|
50
|
2.2.5 For the purpose of selecting acoustic sound insulation, the following sound
noise levels may be used. The frequency spectrum used should be as defined in ISO 717-1:
spectrum No. 2 for discotheques and spectrum No. 1 for others. Evaluation should include
the frequency range down to 50 Hz 1/3-octave band:
-
Cabins –
80 dB(A).
-
Dining Rooms
– 85 dB(A).
-
Corridors –
90 dB(A).
-
Discotheques,
Theatres, Entertainment Areas – 105 dB(A).
2.2.6 Acceptance of bulkhead and deck acoustic insulation values less than those
specified in Table 12.2.2 Minimum apparent airborne sound
insulation indices, R'w
may be considered where agreed between the
Owner and Builder. Not more than 20 per cent of the interfaces tested should have
airborne sound insulation indices, R'w, more than 3 dB(A) lower than
the minimum specified values.
2.3 Crew accommodation and work areas
2.3.1 Under the applicable test conditions specified in Pt 7, Ch 12, 4.2 Test conditions, the
noise levels specified in Table 12.2.3 Crew accommodation - Maximum noise
levels in dB(A) and Table 12.2.4 Crew work areas - maximum noise
levels in dB(A) are not to be exceeded.
Table 12.2.3 Crew accommodation - Maximum noise
levels in dB(A)
| Location
|
Acceptance Numeral
|
| 1
|
2
|
3
|
|
|
|
|
Ships <10,000 grt
|
Ships ≥10,000 grt
|
| Sleeping cabins, hospitals
|
50
|
53
|
60
|
55
|
| Offices, conference rooms and day cabins
|
55
|
58
|
65
|
60
|
| Mess rooms, lounges, reception areas and recreation rooms
within accommodation
|
55
|
58
|
65
|
60
|
| Recreational areas on open deck
|
67
|
72
|
75
|
75
|
| Alleyways, changing rooms, bathrooms, lockers
|
70
|
75
|
75
|
75
|
| NOTE
The levels
may be exceeded by 5 dB(A) within 3 m of a ventilation inlet/outlet or
machinery intake/uptake on open decks.
|
Table 12.2.4 Crew work areas - maximum noise
levels in dB(A)
| Location
|
dB(A) level
|
|
|
|
| Machinery space(not continuously manned) e.g. pump,
refrigeration, thrusters or fan rooms
|
110
|
| Workshops and non-specified work spaces
|
85
|
| Machinery control rooms
|
75
|
| Wheelhouse, chartrooms, radar rooms
|
65
|
| Look-out posts e.g. at bridge wing or window
|
70
|
| Additional limits:
|
|
| • 250 Hz band
|
68
|
| • 500 Hz band
|
63
|
| (measured according to IMO A.343(IX))
|
|
| Radio room
|
60
|
| Galleys and pantries:
|
75
|
| • Equipment not working
|
75
|
| • Individual items at 1 metre
|
80
|
| Normally unoccupied spaces (e.g. holds, decks)
|
90
|
| Ship’s whistle, on bridge or forecastle
|
110
|
2.4 Maximum noise levels
2.4.1 Where
the measured noise level exceeds the specified criterion by 3 dB(A),
or contains subjectively annoying low frequency or tonal components,
the noise rating (NR) number is to be established in accordance with
the graph shown in Figure 12.2.1 Noise rating curves.
This is achieved by plotting the linear octave band levels on the
graph; the NR number is that NR curve to which the highest plotted
octave band level is anywhere tangent. The specified criterion may
be considered satisfied if the NR number does not exceed the specified
A-weighted value minus 5 dB(A).
Figure 12.2.1 Noise rating curves
2.5 Impact insulation
2.5.2 For passenger and crew cabins located below or adjacent to dance floors,
stages, aerobics and gymnasium areas, jogging tracks or other areas where impact noise
is generated, the normalised field measured impact sound pressure level within the
cabins is not to exceed 45 dB.
2.5.3 For public rooms under dance floors, stages, aerobics and gymnasium areas,
jogging tracks or other areas where impact noise is generated, the normalised field
measured impact sound pressure level within the space is not to exceed 55 dB.
2.5.4 For passenger cabins, the normalised field measured impact sound pressure
level, L'n,w, calculated using ISO 717/2, is to be generally in
accordance with the values stated in Table 12.2.5 Passenger cabins normalised field
measured impact sound pressure level L'n,w
. See also
Pt 7, Ch 12, 2.5 Impact insulation 2.5.5.
Table 12.2.5 Passenger cabins normalised field
measured impact sound pressure level L'n,w
| Location
|
dB
|
| Below decks covered with carpet and soft
materials
|
50
|
| Below decks covered in hard materials (such as
wood, marble or similar)
|
60
|
| Below dance floors, theatre or sports
rooms
|
45
|
2.6 Transient noise
2.6.2 The maximum sound pressure level (LpAS,max) emanating from
any machinery or system caused by a single event that produces a noise ‘spike’ compared
to the reference condition sound level (such as vacuum systems or valve operations) is
not to cause an increase in noise in comparison with the reference condition (background
noise) as below:
| (a)
|
Passenger cabins and public
areas:
|
+2 dB(A)
|
| (b)
|
Officer cabins:
|
+2 dB(A)
|
| (c)
|
Crew cabins and public areas:
|
+3 dB(A)
|
A tolerance of +3 dB(A) may be applied to 5 per cent of cabins and public
areas in each fire zone on each deck. This criterion is generally applicable to the
specified maximum noise levels for the space concerned.
|