Booster Blog

reducing impact noise on board to a minimum

Today’s passengers prefer not to hear that they’re on board a cruise ship. That’s why cruise companies are placing ever-stricter demands on noise reduction. Like its clients, Bolidt is always pushing the envelope. What’s our secret? A continuous drive to innovate. Bolidt’s soundproofing systems can reduce impact noise on board to a minimum. 

Droning engines, the footsteps of crew and passengers, lifts going up and down, music from nightclubs and moving gym equipment: sound never stops on a cruise ship. To ensure passengers in their cabins can sleep in peace and quiet, major cruise line companies trust Bolidt’s expertise. Bolidt’s synthetic decks are not only anti-skid, durable, hard-wearing and environmentally friendly, they also provide excellent sound insulation. The quality of its products has made Bolidt the noise reduction expert of choice for the cruise industry for 25 years. 

With systems like Bolideck^® Future Teak and Bolideck^® Select Soft, Bolidt makes an important contribution to reducing impact noise on board. The sound-insulating properties of the Bolidt decks mean passengers in their cabins barely hear the noise coming from the deck above them. No one hears the joggers doing their early morning rounds on the Bolideck^® Select Soft jogging track. And if you sleep underneath one of the restaurants on board, you won’t hear a thing thanks to Bolideck^® Future Teak, no matter how long the diners are burning the midnight oil. With Bolidt’s systems, even the sound of a ball bouncing on the basketball court is reduced to an acceptable level.

Massive noise reduction

Reducing noise on board has become more and more important over the years. “Demand for luxury and comfort has increased enormously. Today’s passengers don’t want to hear they’re on board a cruise ship,” says Jacco van Overbeek, Bolidt’s Maritime Division Director. “And cruise line companies are building increasingly luxurious ships and setting ever-stricter demands on noise reduction. We respond to these demands and are constantly pushing the envelope, just like they are. By continuing to innovate, we succeed time and again in fulfilling the wishes of both passengers and cruise companies alike.” 

Bolidt didn't develop its expertise in soundproofing overnight; it’s been working on the technology for almost 25 years. In developing decks for the cruise industry, the company has always kept its eye on the real issue: reducing impact noise. Van Overbeek: “In the past, we fitted decks made of granulate. They had a rough surface and insulated noise very well because of the air between the granulate. Nowadays, cruise companies often opt for Bolideck^® Future Teak. This material allows them to replace real teak with a more durable hard-wearing alternative that also protects the ship better. Bolideck^® Future Teak presents some new challenges in terms of noise however because the top layer is flat and rock hard. That tends to increase impact noise. 

We’ve solved this challenge by using soft underlays with very specific noise-insulating properties, and by varying thicknesses. This means we can achieve some major noise reduction.” 

Sophisticated computer model

The maximum decibel level in the ‘comfort classes’ nowadays is the one on the open decks, in the public spaces and in the cabins. To ensure their ship complies with the demands of the desired comfort class, cruise companies approach Bolidt at an early stage in the ship's construction. Van Overbeek: “Everything begins with the client's requirements: how many decibels of noise reduction must be realised at a specific location on the ship? We then look at what synthetic systems we can employ to achieve this challenging target. We come up with the ideal mix of top layer and various underlays for every part of the ship. This is done in close consultation with the client. As a ship is being built, we frequently test decks in various compositions to see whether the required noise reduction levels can be met. Based on the findings, the cruise company can decide what system to have fitted to which part of the ship. This means the client gets the best of both worlds: a hard-wearing and aesthetically pleasing top layer, as well as the desired noise reduction level.”

The expertise of noise reduction that Bolidt has built up over 25 years is partly due to its clients, believes Paul de Ruijter, Senior Technical Support Specialist at Bolidt. “Every time we’ve developed new synthetic deck systems for the cruise industry, we’ve been able to test them extensively in shipyards in Germany and France, using a life-size model of part of the ship, with the cabins fitted out exactly the same as the actual ship, including the wall, floor and ceiling insulation. This has allowed us to fit various systems to the deck above the cabin and test them in situ. Using this method, we’ve been able to perfectly map how our systems contribute to reducing impact noise in the spaces below. By working together in this way, our expertise has grown enormously over the years.”

Nowadays, the noise-reducing qualities of Bolidt’s materials are tested not only in shipyards, but also on the computer. Bolidt collaborates in this with Lloyd's Register, an agency specialising in the technical research and analysis of sound and noise reduction. De Ruijter: “Lloyd’s does calculations for Bolidt in which a number of different variables, such as the properties of the materials in our synthetic deck systems, are entered in a sophisticated computer model. We then test this against the results of the practical test that we carried out above the cabin. With the computer model, we can vary the construction of the decks endlessly and determine the ideal mix of top layer and underlay to achieve the desired noise reduction. This has thrown up material mixes that we couldn’t have found without the model. Together with Lloyd’s, we’ve been able to successfully predict the noise level in cabins for several cruise ships.”

Increasingly challenging

Over the 25 years that Bolidt has been developing its synthetic deck systems, the question from cruise companies has never really changed: make sure that the decibel level on board decreases. De Ruijter: “Of course, fulfilling this strict requirement is getting harder and harder. It’s like telling an athlete to keep improving on their best time. But that’s what’s so great about this: we strive to set world records every day.”