Cruise ship noise in a port - low budget solution with a big impact

One of the highlights of a cruise vacation is the opportunity to visit and explore stunning coastal cities. To maximize convenience for passengers, large cruise ships typically dock close to city centers, providing easy access to local attractions.

However, this close proximity also means that the noise generated by the ship is more noticeable to local residents. In one particular port, authorities required a visiting cruise ship to comply with a strict airborne noise limit: a maximum of 75 dB(A) at a distance of 150 meters from the vessel.

The operator was unable to meet this requirement and turned to JASCO ShipConsult for expertise in noise reduction.

To bring the vessel into compliance with port regulations, ShipConsult engineers conducted a thorough investigation to identify key noise sources and develop targeted mitigation measures.

On-site noise measurements

ShipConsult engineers traveled to the vessel’s location to conduct an in-depth investigation. They measured and documented airborne noise levels at various distances within the port. However, external noise from traffic and port operations interfered with the readings, making it difficult to isolate the ship’s noise output.

To obtain more precise data, engineers conducted direct onboard measurements of individual noise sources. These tests revealed that most of the unwanted noise came from ventilation vent outlets on both sides of the vessel, with additional emissions from the exhaust gas outlets near the funnel.

Identifying key noise sources

A detailed assessment of all ventilation outlets and the funnel enclosure followed. The ShipConsult acoustics expert identified several areas where relatively simple structural modifications could lead to substantial noise reductions. The findings indicated that reducing noise emissions at the source was the most effective approach.

Developing a noise mitigation strategy

After discussions with the vessel’s Technical Superintendent, a set of practical design changes was proposed. The recommended solutions included:

• Installing sound-absorbing materials around key noise sources
• Adjusting the design of ventilation outlets to minimize noise propagation
• Implementing shielding structures to block noise from spreading toward residential areas
• Optimizing the placement of exhaust gas outlets to reduce overall emissions

A comprehensive report outlined these cost-effective measures, focusing on absorbing and shielding noise as close to the source as possible.

Verifying the results

Post-refit noise measurements confirmed a reduction of 8-22 dB(A), bringing the ship well within the port’s regulatory limits. This successful reduction meant that the vessel could continue docking at the port without any further restrictions.

Thanks to the efficient and pragmatic noise mitigation process, the cruise operator remained on schedule without itinerary disruptions. The modifications were discreetly carried out during regular port operations, ensuring no impact on passengers or crew.

With significantly reduced noise emissions, the cruise liner regained access to the port and could continue offering passengers breathtaking views of the coastal city—without disturbing the local community.