The Indian Register of Shipping (IRClass), a leading ship classification society, and Dassault Systèmes co-hosted an international conference on design solutions for noise reduction in defence and commercial ships.
Held at IRClass’ head office in Mumbai, India, the one-day ‘Design Solutions for Noise Reduction in Defence and Commercial Ships’ conference drew participants from various sectors including the Indian Navy, shipyards, designers, consultants and ship operators.
Mr Vijay Arora, Joint Managing Director of IRClass, inaugurated the conference by highlighting the importance of noise prediction and its evolving techniques in view of present IMO noise code.
The conference deliberated on possible design and software solutions for conventional passenger and cargo ships to meet regulatory requirements outlined in International Maritime Organization’s Code on noise levels on board ships – IMO Resolution MSC.337 (91) – which requires the measurement of noise levels and recommends limits on acceptable maximum noise levels for all spaces to which seafarers normally have access to.
To comply with the IMO Resolution, the conference noted that noise prediction is required right from the initial design stage and discussed the methods for noise prediction ranging from empirical methods such as IRClass’ proprietary noise prediction software to advanced methods based on statistical energy analysis (SEA), boundary element method (BEM) and computational fluid dynamics (CFD). The effects of insulation and alternative arrangements to keep noise levels within specified limits through such predictions were also discussed.
In addition, the conference also covered issues relating to underwater radiated noise (URN) generated by defence vessels for which its prediction and measurement are required as a stealth feature. The effects of URN by commercial and defence vessels on marine life were highlighted during the panel discussion.
Mr N. Girish, Divisional Head of Research and Innovation Centre of IRClass, said, “Assignment of appropriate class notations to ships indicating the noise level comfort for crew and passengers will be useful to all stakeholders. Also, there is a need for “silent” vessel notations which signify the protection of the environment from underwater as well as airborne noise emissions from ships.
While these notations will be assigned based on final measured noise levels, prediction at design stage holds the key to achieving those levels.”
The conference concluded with delegates from the defence and commercial shipping community expressing support for ongoing technical discussions on how noise reduction methods and safety management practices will evolve in tandem with technological advancements.