Ship Design Tips To Reduce Underwater Noise
We recently published a blog on the impact of underwater noise on marine life that was so well received that we thought we’d follow it up with a closer look at the International Maritime Organisation (IMO) design guidelines that have been put in place to mitigate this particular environmental stressor. The IMO has been hard at work to tailor these guidelines for the reduction of underwater noise, which has been shown to have a significant impact on the wellbeing of countless marine life species.
Noise Reduction Begins With Ship Design
The most effective way to reduce underwater noise is to address ship design in a holistic fashion before it even goes into production. Ships that are currently making their way around our oceans are unlikely to be retrofitted to the point where these vessels will be able to achieve the reduced levels of audio output that purpose-designed vessels will be able to achieve in future. In certain cases, however, the hulls of existing ships can be adapted to address the inflow of water to the propeller. Ideally, these two components should be designed to work in sync, which will also improve energy efficiency in the long run.
Components That Can Be Adapted To Reduce Noise
There are certain components of a ship that can be adapted to reduce overall underwater noise emissions. These include:
- Propellers: Propellers should be designed and selected in order to reduce cavitation. Cavitation will be the dominant radiated noise source and may increase underwater noise significantly. It can be reduced by optimising propeller load and ensuring uniform water flow into the propeller itself by considering factors such as the diameter, pitch, skew, blade number and sections.
- Hull: The ideal hull form allows for a homogeneous wakefield that reduces cavitation because the propeller operates in the wakefield produced by the hull itself.
- On-Board Machinery: Consideration should be given to the selection of onboard machinery along with appropriate vibration control measures, proper location of equipment in the hull, and optimisation of foundation structures that may contribute to reducing radiated underwater noise, as well as onboard noise affecting passengers and crew.
These are just a few of the design considerations ship manufacturers will have to bear in mind if they want their vessels to conform to future maritime noise laws. At the moment the guidelines pertaining to the reduction of underwater noise are not mandatory, but as research in this regard continues, the IMO believes that it will soon become enforceable by law. The Link Ship Chandlers team is always on the lookout for fresh news and information on freighting challenges around the world. Keep an eye on the blog in coming weeks and months for more shipping-related news and expert insight into running a smooth logistics operation from start to finish.