Shipping has an increasing impact on underwater fauna through underwater radiated noise generated by ship machinery and propellers. Marine mammals use sound for communication and navigation. With shipping noise interfering with their communication and ability to navigate marine species find it increasingly difficult to find food, suitable mating partners and are more likely to get lost which sometimes results in beaching.

With growing awareness of these issues, and growing traffic, the first (non obligatory) underwater noise limits have been formulated. In areas such as Vancouver harbor, harbor fees are related to the amount of noise a ship radiates to the underwater environment as a way of stimulating reduction of underwater noise.

We provide consultancy in ship design and underwater noise radiation. In order to build low underwater noise vessels, it is important to involve ship noise consultants even before a shipyard is invited to tenders for a building contract, both in the interest of the ship operator and the shipyard itself.

We use structural modelling techniques to evaluate engine mounting, shaft and bearing dynamic behavior and ship structural response based in relation to simulated underwater radiated noise.

In addition to using traditional measurement and analysis methods according to regulatory/class requirements, we are involved in developing a underwater noise measurement system deplorable through an airborne drone. We have demonstrated that this measurement concept considerably reduces the impact of tidal current flow noise on the measurement results. This is considered particularly useful for investigating underwater noise from tidal turbines. 

PZdynamics carried out the underwater noise measurements for the RRS Sir David Attenborough plus spectral analysis to evaluate compliance with DNV Silent-R and Silent-S notation. The underwater noise measurements counted as the first official  scientific deployment of the Sir David Attenborough.

Underwater noise measurements from a support vessel (foreground) for the study of the effect of various propeller design on the ship passing by on the background. Study was carried out with the University of Strathclyde.