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
2.2.1 Under test conditions specified in Pt 3, Ch 6, 4.2 Test conditions, the
applicable noise levels specified in Table 6.2.1 High speed craft - Maximum noise
levels in dB(A) and Table 6.2.2 Yachts - Maximum noise levels in
dB(A) should not generally be exceeded. See
Pt 3, Ch 6, 2.2 Passenger accommodation and public spaces 2.2.3.
Table 6.2.1 High speed craft - Maximum noise
levels in dB(A)
| Location
|
Acceptance Numeral
|
| 1
|
2
|
3
|
| Public spaces:
|
Excluding shops
|
60
|
65
|
70
|
| Shops
|
65
|
68
|
72
|
Table 6.2.2 Yachts - Maximum noise levels in
dB(A)
| Location
|
Acceptance Numeral
|
| 1
|
2
|
3
|
| Passenger cabins:
|
Standard
|
53
|
55
|
58
|
| Superior
|
50
|
53
|
55
|
| Lounges
|
55
|
58
|
60
|
| Open deck recreation
areas:
|
2nd deck from WL
|
72
|
75
|
79
|
| 3rd deck from WL
|
63
|
66
|
70
|
| Wheelhouse
|
60
|
62
|
75
|
Note
1. The levels may be exceeded by 3dB(A)
in accommodation above the propellers for three decks above the
mooring deck.
Note
2. 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.
|
2.2.2 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 3, Ch 6, 2.6 Transient noise.
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 6.2.3 Minimum apparent airborne sound
insulation indices, R′w, calculated using ISO 717/1. See also
Pt 3, Ch 6, 2.2 Passenger accommodation and public spaces 2.2.6.
Table 6.2.3 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 corridoors/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 6.2.3 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
2.3.2 Crew space
insulation is to comply with the requirements of IMO Resolution MSC.337(91) – Adoption of the Code on Noise Levels on Board Ships – (Adopted on 30 November 2012)The Annex below
is consolidated into Resolution MSC.337(91).
Table 6.2.4 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
|
Table 6.2.5 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
|
| Wheelhouse, chartrooms, radar rooms
|
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:
|
|
| • 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 6.2.1 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 6.2.1 Noise rating curves
2.5 Impact insulation
2.5.1 Where agreed
between the Owner, Builder and LR, enhanced criteria for noise levels
recognising the effects of impact sound pressures may be applied in
accordance with Pt 3, Ch 6, 2.5 Impact insulation 2.5.2.
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, 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 6.2.6 Passenger cabins normalised field
measured impact sound pressure level L′n,w
. See also
Pt 3, Ch 6, 2.5 Impact insulation 2.5.5.
Table 6.2.6 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 with 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.
|