Trans RINA, Vol 157, Part A3, Intl J Maritime Eng, Jul-Sep 2015
The required levels of noise are very similar in all CS; small differences existing between the requirements for passenger cabins (first class or standard) and outdoor facilities (Table 3).
Table 3. Summary of the "Comfort Class” of different CS. Type of space
Noise limit dB(A)
First class passenger cabins
Standard passenger cabins
Crew cabins Wheelhouse Engine room
Unmanned machinery spaces
Engine control room Workshops
Minimum 44
49 50
55
67 80
Maximum 56
60 60
108 110 85
65 90 80
85
The location of the points of measurements and tolerances are the criteria that mostly differ from one Classification Society to another. The majority of Societies employ tolerances, although they differ with respect to their criteria. Some Societies allow exceeding a percentage of maximum levels (BV, DNV, RINA), for others, excessive levels lead to new measurements (LR) while no tolerance is supported in other cases (ABS, GL).
While Classification Society requirements regarding
vibration vary considerably (although they are lower than the ISO standard) [8], there is substantial consensus on noise requirements.
3.5 EUROPEAN DIRECTIVES ON NOISE
Through its "Green Policy", the European Union has imposed increasingly stringent requirements to reduce the environmental impact of all types of transportation. These requirements are presented in three areas:
‐ Noise and vibration on board ships ‐ Noise radiated from ships in ports ‐ Underwater radiated noise
We shall now briefly enumerate the regulations regarding the last two groups, as that relating to the first group has been analysed in the preceding sections.
3.5.(a) Specific regulations for the control of noise radiated from ships to the port and inhabited areas in inland waterways
2001 - EN ISO 2922:2000 [9]. This standard specifies the conditions for the measurement of airborne noise emitted by vessels of all types on inland waterways and harbours, except for powered recreational craft, as these are regulated by ISO 14509. It is applicable to small offshore vessels, harbour craft, dredgers and all
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‐ To establish a common approach intended to avoid, prevent or reduce on a prioritised basis the harmful effects, including annoyance, due to exposure to environmental noise.
‐ To provide a basis for developing EU measures to reduce noise emitted by major sources, in particular rail and road vehicles and infrastructure, aircraft, outdoor and machinery.
industrial equipment and mobile
2006 - Directive 2006/87/EC. The noise generated by a vessel under way shall not exceed 75 dB(A) at a lateral distance of 25 m from the ship’s side and the noise generated by a stationary vessel shall not exceed 65 dB(A) at a lateral distance of 25 m from the ship’s side, apart from transhipment operations.
2007 - EN ISO 14509-2:2007. This specifies procedures for assessing the maximum noise emitted by powered mono-hull recreational craft of up to 24 metres in length.
2009 - EN ISO 14509-1:2009. This standard evaluates emitted noise
procedures. 3.5.(b) Regulations and standards
underwater radiated noise
Although the main source of underwater radiated noise is obviously the propeller, as well as the propulsion machinery due to inducing structural vibration, there are also other features that influence the emission pattern and intensity of the radiated noise are: the directivity of the sound, the dimensions of the vessel and its speed (the faster the speed, the
higher the emissions), load
conditions (higher emission levels when the ship is in ballast condition), type of propeller (controllable pitch propellers are the most problematic) and vessel maintenance.
The receptors of this noise are marine wildlife in general, although marine mammals are affected the most, as they rely on sound to communicate, coordinate
their
movements, navigate, explore the environment, find food and avoid predators. The absence of environmental requirements regarding ship underwater radiated noise has been widespread in almost all contractual specifications until now, with the exception of the most modern
However, the emergence of international, national and regional
oceanographic and fisheries research associations for
ships. the protection of marine
mammals has led to the drawing up of a series of regulations that address underwater radiated noise and its
using calculation and measurement pertaining to ship
those watercraft, including those that are berthed, used as or with the capacity to be used as a means of water transport.
2002 - Directive 2002/49/EC [10]. This Directive has the following aims:
©2015: The Royal Institution of Naval Architects
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